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The Quest M3s, a simplistic and robust sample roasting machineThe Quest M3s, a simplistic and robust sample roasting machine
Within the class of table top coffee roasting machines, the Quest M3s sample roaster is about as simple as they come. There are no preset roast profiles, built in data loggers, blue tooth technology, or any other gadgetry to speak of. In this way it's much more like a larger production drum roaster, thermal dynamics controlled by two main adjustable parameters, good old fashioned heat and air flow.

Adjusting the Quest's temperature output is pretty straight forward. A range of 0 to 10 amps can be sent to twin heating coils inside the machine, the adjustment made via a dial on the side of the roaster. And while fan speed is similarly controlled, the Quest's airflow is affected by more than just a turn of the dial. Let's first take a quick look at how the Quest's airflow circuit works, and then how other factors outside of fan speed can greatly assist in making quick adjustments to the thermodynamics of your roast.

A basic outline of the Quest M3s airflow circuit - in the back of the drum, and near full circle to exhaust at rear chaff boxA basic outline of the Quest M3s airflow circuit - in the back of the drum, and near full circle to exhaust at rear chaff box

The Quest M3s airflow circuit starts just behind the drum housing via two stainless steel intake tubes. The inlet to these tubes is sandwiched between the rear of the drum and the chaff collection box, a tight space, but ample enough for pulling in the outside ambient air. The air is then pulled across the drum back-to-front, up the loading chute, across the top tube, down through the chaff collection box, and then exhausted out a vent in the back. That's a bit to follow if you don't have one sitting in front of you, and hopefully my crude drawing above helps to illustrate the air path.

Increasing fan speed pulls more air across the bean bed, and decreasing does just the opposite. The steel air intake tubes are situated between the heating coils and get really hot, warming the incoming air just a bit. We incorrectly stated in an earlier blog post that an increase in airflow actually speeds up the roast since the incoming air is warm (our first test of this theory seemed to support this, however more recent tests prove otherwise). You'll see from my test results that this isn't actually the case, and that increasing the air flow slows the temperature's rate of rise (ROR) by a few degrees per minute, a significant difference when spread over the entire roast time.

At the risk of stating the obvious, decreasing the fan speed creates an inverse effect - incoming air is all but cut off, which in turn pulls less heat from the drum, allowing the temperature to rise at a more steady clip. But as many Quest owners have pointed out, the fan in the Quest M3s is always running, and so it's impossible to shut off airflow completely. While it's true that the fan is always running, you can cut off airflow to the drum altogether by opening the cooling tray door on the top of the cooling/fan compartment at the back of the roaster. Opening this door effectively disrupts the airflow circuit, changing the air intake from the rear of the drum to directly into the cooling tray area. This one parameter change completely cuts off air to the drum and bean bed, thus creating the hottest roasting environment.

Have a look at one of two steel intake tubes positioned smack dab in the center of the heating coilHave a look at one of two steel intake tubes positioned smack dab in the center of the heating coil

To gain a better understanding of the effects airflow has on ROR for this machine, I roasted three 90 gram batches of the same coffee, one with full fan speed, one with fan speed at 0 (fan still on but at minimum speed), and one with the rear door open cutting off air to the drum. Even though my drop temperatures vary by a few degrees (I was shooting for 400f on the theramaprobe, but it's hard to hit on the money with such a small roasting chamber!), logging temperature changes for the three roasts shows a clear difference in ROR, which though small from minute to minute, equates to pretty drastic changes in overall roast times.

A couple things to point out about the graphs. First, these temperatures are in Fahrenheit, measured with a digital thermocouple in the bean bed position. I also didn't record where the temperatures bottomed out and turned around, but it was within the first 2 minutes. That's why the first two minutes are greyed out, and no ROR is listed as that data would be incorrect based solely on 1 and 2 minute temp markers. I've also marked where 1st crack occurred in the orange/brown cells, and then list exact time and temp of first snaps at the bottom of each graph.

Graph outlining my three roasts: #1 max airflow, #2 minimum airflow, #3 airflow circuit interruptedGraph outlining my three roasts: #1 max airflow, #2 minimum airflow, #3 airflow circuit interrupted

As you can see from the data logged above, the smallest ROR difference is seen between the first two roasts with fan speed dialed at 10 and 0, and the widest time spread is between roasts #1 and #3, where the airflow circuit is interrupted. That's to be expected, but just how significant are these differences? Using the temperature logged at minute 2 as a starting point, roast #1 with maximum airflow advanced 59 degrees in 4 minutes before hitting first crack (1C), whereas roast #3 jumped 58 degrees to 1C in just 2:40, a pretty huge difference. If you look at the 2 minutes following 1C, roast #1 climbed at roughly 8 degrees per minute, while #3 barrelled forward at 20 degrees per minute.

The roast progression is much closer between #1 and #2, but still worth our attention. The difference in ROR is only about 4 degrees in the first few minutes, dropping to 2 degrees by minute 4. This slight degree of difference seems almost negligible in this context, however, if 420F was your roast target, roast #2 would hit that mark nearly a full minute faster than #1. Depending on the coffee and desired results, that can be the difference between developing a coffee's sweetness, or baking the sweetness out to some degree. It's also worth noting that because each roast batch is subjected to a hot drum at the outset, ROR is much closer in all three roasts from minutes 1 to 3. After that, roasting with airflow slows the progression, whereas the roast with no air continues to take off.

These are the sorts of factors I take into consideration when roasting, in particular when transitioning from one coffee to the next, and especially if they differ in factors such as water content, density, and processing method. I might cut the fan speed to add heat during the drying phase for a wet coffee, increase the fan speed to take the edge off a potential runaway roast of a dryer coffee before 1C, or open the back door to pick up the pace of a stalling batch. Changing the amperage can be effective too, but oftentimes with electric roasters you have greater influence on roast dynamics with air flow, and are less likely to over correct the heat settings, and find yourself struggling to return to a properly warmed machine.



by Dan Wood

a steady stream of Ethiopia Sidama Nansebo from the Flaira steady stream of Ethiopia Sidama Nansebo from the Flair

East African espressos aren't for everyone. I get it. The acidity level of washed Kenyas and Yirga Cheffe's can be overwhelming, especially when roasted anywhere north of Full City+. Of course there are exceptions to this rule, and when it comes to espresso, our recent arrival Ethiopia Sidama Nansebo is an Ethiopian SO espresso worth considering.

As brewed coffee, Nansebo stands out. It has some of the hallmark cup characteristics of Sidamas - floral, stone fruit, citrus, and more - but in lower volume than others on our list. But what really stood out to us is your ability to easily manipulate the cup characteristics with roast development, taking a bright, citric cup, to a muted, bodied, and incredibly honey-sweet coffee with just a few shades of roast development. Add to this versatility a big-body regardless of roast level, and you have a great espresso candidate.

For the sake of showcasing this flavor shift by roast development, I roasted one batch to City+, and the other a stretched Full City. I'm roasting in a Quest M3s sample roaster, so batch size is small (85 grams), and only airflow adjustments were used to influence roast development. Our City+ roast had a first crack time of 6:15, temperature of 396F, and finish time of 9:00, temperature of 419F. Full City roasting was achieved with a first crack time of 6:05, temperature of 395F, and finish time of 9:40, temperature of 428F. I maxed airflow across the drum at the beginning of first crack, a minute sooner than the City+ roast, in order to draw out sweetness and further mute perceived acidity (I found that maxing Quest's fan speed/airflow through the drum slows ROR by about 2 degrees per minute in comparison to setting the fan speed dial to 0...but we'll save that discussion for a different Quest M3s blog!).

my double barrel, home lab setup - two Quest M3s roastersmy double barrel, home lab setup - two Quest M3s roasters

And full disclosure, we used the Flair portable espresso maker for pulling shots. I know, small basket, no boiler to regulate water temperature...how can you pull a good shot on that? Well, we've sat with this machine for a few months now, and done enough side by side testing with our Rocket Evoluzione to know that with proper preparation, the Flair is capable of producing impressive results. Our staff are continually wowed by our ability to yield good espresso extraction with the Flair, and it's certainly a suitable machine for the purpose of this comparison.

All shots pulled were 15 grams going in, and though I didn't weigh the volume of extracted coffee coming out (it's hard to fit my scale under the brew head of the flair), I have in the past, and I'm generally in the 17 - 20 gram range.

City+ -
Shot 1: - Pulling shots on the short side (<15 grams) yields mouth puckering results. I enjoy ristretto shots myself, but this was much too short for me, and an accident of my grind setting being off! Citric brightness dominates and is way out front, and flavor notes are difficult to parse out. It's creamy in texture for sure, but any actual flavor notes are hard to focus in on through a lingering metallic taste.

Shot 2: - The parameters of my second pass were much more in-line with what I'm used to. I probably pulled close to 20 grams in 30 seconds, steady pressure applied to the lever the whole time. Still quite bright from the outset, the the tart flavors that followed were like underripe Naval orange, lemon bar, and unsweetened cranberry juice. A chocolate cookie flavor comes into play part way into the sip, giving off a mix of mild chocolate wafers/lemon wafers flavors. A perfumed floral note pushes through in the aftertaste too, but quickly disappears.

the Flair portable espresso maker; aluminum body + steel brew chamber = portable and functional machine!the Flair portable espresso maker; aluminum body + steel brew chamber = portable and functional machine!

Full City -
Shot 1: The volume yielded on my initial shot was on par with my 2nd shot of the lighter roast, building an extremely creamy mouthfeel and each small sip produced an overwhelming amount of flavor. There's a tangy orange characteristic at the top of the taste, but much more a precursor to an expansive flavor matrix loaded with dark fruit and chocolate characteristics. The flavors unfold as you move through each drink; first dark orange, then blueberry, cranberry lambic, peach nectar, and a ribbon of dark chocolate threading through each layer, adding a sort of mortar to the overall flavor compound. An accompaniment of honeyed sweetness is also memorable, as are bitter to sweet cacao flavors that seem to expand the longer you savor them. A full two minutes later and I'm still tasting bittersweet chocolate, a wisp of unsweetened baking cocoa shows just before the cup flavors disappear entirely.

Shot 2: I found the previous shots to be delicious, but surprisingly non-jarring, and figured I'd see if a super short shot changed this aspect. I was surprised to see that the citrus appeal was nearly lost altogether. There were faint berry tones intermixed with much more dominant cocoa roast tones, and a savory miso flavor. Like my first accidental ristretto shot of the City+ roast, metallic flavors also come into play, killing any real enjoyment for me.

In short, Nansebo can bear citrus flavors and citric impressions in titanic proportion when roasted light. It's a big bodied coffee to begin with, and light roasting does little to hinder this, so a great option for those who both enjoy Ethiopian SO espresso as well as light roasted espresso. Just a couple shades darker, and the sweetness really opens up, honeyed and resonant, as do more dark fruited allusions. Citrus notes still show up, but in much lower intensity - i.e. in flavor but not so much in acidic impression. I found more berry and stone fruit flavors in our Full City roasts, as well as deliciously bittersweet cocoa flavors. Overall Nansebo is incredibly versatile, a great dual use option, and definitely worth considering by those looking to have an Ethiopian coffee on their espresso bar.

Ethiopia Sidama Nansebo is available in 100 LB and 50 LB bags, as well as samples. Ordering info and full review HERE.


Wet fermentation - this coffee is just about ready for a final rinseWet fermentation - this coffee is just about ready for a final rinse

This post-SCA Expo blog entry is a little overdue. Returning from SCA is usually a bit of a rush, coming back to a week's worth of offer and arrival samples to roast and taste, and a steady stream of producers and exporters stopping through before they return to their homes abroad. Needless to say, our intention of following up our Coffee Shrub SCA tasting and discussion with a "quick blog post" was sidelined just a bit. But you know what they say, better late than never.

Coffee Shrub hosted our first ever SCA event at April's Expo, a gathering that drew a surprising number of folks given the slightly cagey instructions to an offsite location. It felt a little like a secret warehouse party in this respect, and so a big thank you to all those who heeded our instructions, waited for a location confirmation, and ultimately walked the several blocks from the Convention Center to join us!

For those of you who couldn't make it, we focused our tasting around different processing methods, and discussed the role fermentation plays on taste, and ultimately price. We were lucky enough to have colleagues from different coffee growing regions to take part in the discussion, including Fredy Morales who manages Finca Rosma in Guatemala, Ture Waji from Mormora plantation in Ethiopia, and both Leonardo Henao and Pedro Eshavarria from Pergamino Coffees in Colombia.

Fermenting coffee without water in Timaná de Huila, ColombiaFermenting coffee without water in Timaná de Huila, Colombia

Each has a different first-hand experience of how processing affects coffee in their regions, and what became clear as we moved through the discussion is that there is no "one size fits all" coffee processing solution that magically adds value to coffee. There are a lot of factors for farmers to consider, especially the small holder, and what might be considered a contradiction to processing "best practices" in one area may be the most lucrative option in another.

One such "contradiction" is the practice of mixing days of harvest during the fermentation process. This isn't talked about a lot, at least not in a positive light, as the current opinion by most agronomists is that harvesting and processing each day of harvest separately is the best way to operate. This means picking and de-pulping the coffee same day, fermenting overnight to remove the sticky layer of mucilage, and then laying the wet parchment to dry on patios or raised beds.

For small farmers, this also means managing several tiny batches of coffee, which is a bit of a strain at the fermentation tank, and a lot to keep track of on the drying patio. Most folks only have a single tank, and so in order to maximize the output during this stage in processing, you can either wait to pulp cherry until there is enough to fill the tank, or as we found in northern Antioquia in particular, pulp as you go, mixing multiple days of harvested coffee in the tank to ferment before drying.

Typical depulper set up in Urrao, Antioquia - this one has two small tanks for keeping mixing of days to a minimumTypical depulper set up in Urrao, Antioquia - this one has two small tanks for keeping mixing of days to a minimum

One of our guests, Leonardo Henao, has devoted quite a bit of time and research into learning how the practice of mixing lots intersects with cup quality. Having a farm in Urrao, Antioquia himself, he's witnessed mixing by his neighbors, some of whom produce coffees of exceptional quality (one of them won COE in 2014). So he and his colleague Doriett, a phD student from the Universidad Nacional de Medelliín set out to better understand what's happening during the fermentation process when mixing multiple days' lots, and more specifically, find out what benefit there is, if any, to the coffee's cup profile.

During fermentation, bacterias break down pectins in the sticky mucilage/fruit layer that is stuck to the bean, eventually allowing it to slip away from the seed. This also frees up sugar molecules, which are then broken down by yeasts, and produce organic acids and oils as a byproduct. In this way, fermentation isn't being used to affect cup flavor, but as a means by which to necessarily "wash" away this layer of fruit before drying. Under normal circumstances, the fermentation is complete once this is achieved, and simply leaving a coffee for longer puts a potentially clean cup profile in jeopardy of turning sour. What Leo and Doriett found by watching Leo's neighbors process coffee, and through laboratory research, is that certain steps taken along the way actually slow the fermentation process, allowing the coffee to sit safely for a longer period in the tank, and often improving the resulting cup profile.

First off, it might help to give a quick explanation of what exactly we mean by "mixing days". In Urrao for example, farmers mix up to 5 days of harvested cherry before the final washing off of mucilage and drying. First they de-pulp the harvest from day 1 into their fermentation tank and add cold water, allowing it to ferment overnight. The next day they de-pulp harvested cherry from day 2 on top of day 1, changing out the old water with fresh, cold water again. This continues until their fermentation tank is full (usually 2 - 5 days depending on the farm size), allowing the entire lot to ferment one final night with the freshly de-pulped coffee before rinsing the mucilage and sending to the drying beds. On it's face, we'd expect this process to result in flavors associated with over-fermentation, fruit notes on the alcohol side, and perhaps water activity on the high side. But what we found is quite the opposite, and regional conditions and local practice are part of the explanation why.

Urrao is extremely high in altitude, 1850 meters above sea level at the valley floor, and cold, historically too cold to produce anything more than blender type coffees. A warming climate has actually benefitted coffee growers in this area, with annual temperatures right in the sweet spot for stimulating high productivity for the coffee trees (averaging 19.5 - 21 C). Yeasts and bacterias need to reach a certain temperature to react with sugars, and the cold climate and water slow this process down. Changing the water also helps slow things down, as each day when cold water is added, the PH level is in turn raised, reducing the acidity needed to break down the sugars in the mucilage. And finally, each day new coffee is added to the batch, new sugars are introduced, maintaining a healthy environment for the surrounding yeast and bacteria.

Measuring and comparing org. acid levels in different process batchesMeasuring and comparing org. acid levels in different process batches

For Leo's experiment they tested several process batches that differeed in number of days mixed, and overall time in the fermentation tank. The goal was to then measure the organic acids present in the final milled coffee, and of course, record cup scores and notes generated by a sensory panel of cuppers. The slide above from their final presentation illustrates the change in organic acid content, the low end being coffee processed without any fermentation (mechanical demucilage), and the long end being 5 days of mixing. It's clear that of the 6 organic acids measured, the greatest overall volume is at 3 days, all but lactic and quinic seeing a steady increase in volume over the first few days before dropping off precipitously by day 5.

So how does this play out in the cup? As you can see from the slide below, the overall score range is pretty tight: 80.5 at the bottom, and 86.38 at the top (4A). The two top scoring coffees on this graph are a mix of 2 harvest days. The lowest scoring coffee was not fermented at all, the mechanical demucilage method being used to remove the mucilage and then immediately taken to the patio for drying.

Cup testing the process batches - highest score is with 2 days mixing, and lowest no fermentation at allCup testing the process batches - highest score is with 2 days mixing, and lowest no fermentation at all

What this graph seems to say is that the mixing method is superior to processing each day separately, which when we're talking about the difference of 80 and 86 in this particular case, means a hefty financial gain to the farmer. But it's important to keep in mind that given different variables - climate, harvest volume, altitude, bean desnisty, water temperature, etc - the effect fermentation has on a coffee will also vary. In a growing region like Costa Rica for example, where milling equipment operates at maximum capacity daily, and mechanical demucilagers are the norm, mixing days makes no sense at all. The same can be said for other parts of Colombia, and even within Urrao itself, and so for the farmer it's important to consider cost of production and quality implications when weighing one processing method over another.

Leo's presentation gave us a lot to think about in regards to the role fermentation has on a coffee's quality, with particular attention to the unique situation presented by small holders in Urrao. It's a reminder that for coffee, as with most agricultural products, environmental factors affecting quality are often out of the farmer's control, and differ from one region to the next. Processing, however, puts some control back in the farmer's hands, still limited by the outside factors mentioned above. 

During this discussion we compared the coffees of Urrao to other Colombian coffees subjected to much shorter fermentation times. Unsurprisingly, some folks favored one over the other, and thankfully not everyone agreed. There really is no accounting for preference, and as coffee buyers it's important to remember that no matter how much we love a clean washed coffee, or wild and rustic dry processed cup, "best practices" are limited by region, environmental factors, and the economic resources available to the farmer (and more). And so for most tiny farmers it simply does not make financial sense to chase current processing trends in the hopes of selling their coffee for a higher price. 

This can be discussed in much broader terms as well - e.g. not just decisions farmers face with regards to the intersection of processing style and cup quality, but also cultivars to plant, conventional vs. organic farm practices, storage methods, and so much more. In each of these cases, there is no blanket solution to controlling coffee quality.

If you'd like a copy of the presentation slides, email me at dan@coffeeshrub.com. FYI - there isn't a lot of accompanying text with the slides, and they will be most useful to those who were in attendence. 

-Dan Wood

 


Bag marks vary, this one showing importer, lot ID and ICO number infoBag marks vary, this one showing importer, lot ID and ICO number info

If you've ever purchased full bags from us, you may have spotted logos other than the "Coffee Shrub". These are the logos exporters and importers who provide us with logistics services to get our coffee to the Port of Oakland.

A long time ago we considered doing our own importation. It's not that difficult. But it also can be a major distraction when things go wrong. We realized, after a few containers we arranged ourselves, that wrestling with the importation logistics wasn't worth the effort, or risk. And those shipments were for merchandise along easy transit lines, unlike the routes that serve coffee ports.

In brief, we find using coffee importers as "logistic service providers" allows us to focus our efforts on the what we're good at, like selecting the best possible coffees we can. Plus, in the shipping world, volume counts. If we use an importer who is already moving many containers from a place like Colombia, buying coffee for their own Spot position or bringing in coffee for bigger clients like Green Mountain or Starbucks, they have clout to get things moving promptly. What incentive does a shipping line like Maersk have to deal with our 1 container versus 10 boxes from Olam or Ecom or Volcafe?

Importers write up contracts between us and the coffee farmers we buy from, which helps to manage financial risk at both ends of the transaction. For the farmers, they make sure that the price we agree on for their coffee is paid. And for buyers like us, they make sure the coffee we select is not only shipped in a timely manner, but that the quality of the shipped coffee is on par with the original offer samples we taste.

Olam's logo on an Ethiopia coffee we sourced with themOlam's logo on an Ethiopia coffee we sourced with them

Once the coffee is state side, importers handle the paperwork needed to pass inspection with government agencies like Food and Drug Administration, United States Department of Agriculture, and Customs and Border Patrol. Coffee is a food product after all, and so there are strict rules as to what foods can be brought into the country. Employing the help of importers is crucial for us here, as they are experts in navigating the myriad of paperwork involved, ensuring all documentation, bills of lading, certificates of origin, and so on are in order to avoid any hold ups when our coffees land ashore.

This added link in the supply chain might seem to challenge the term "Direct Trade". But like many other small green coffee merchants, the services handled by import and export companies is what allows us to meet the challenge of remaining small. We buy most of our coffees direct, provide extensive marketing materials for each and every lot of coffee, and ship orders as small as 50 lbs locally on up to several pallets of coffee internationlly, all with just a few individuals. So when you see names like "Olam", "Falcon Commodities", "Volcafe Specialty", and others printed on our bags, remember that it's these partners who allow us to do this work, and to do it well.

-Dan and Tom


Roasting Washed Central American Coffees by Chris Schooley, Photos by Thompson Owen

Penagos Depulpers at ProvidenciaPenagos Depulpers at Providencia

High grown washed Central American coffees are practically the control coffee when it comes to roasting, the coffees that roast just like they should. They take the heat up front, change color evenly, charge into 1st Crack with gusto and with a definitive finish. On top of all that, they are perhaps the most versatile as far as roast level and roast development, with a plenty of exciting and intensely sweet characteristics expressed from City to Full City+. They also have a lot of room to move the characteristics across the palate and create a 3 dimensional profile.

The number one fundamental of washed Centrals in my mind is sweetness and the way that you can present the whole range of development of that sweetness. Some washed South American coffees also share this trait and you can include them here, especially Colombians. African coffees often have the vibrant and exotic fruit and floral attributes, and Indonesian and Pulped Natural coffees have the more rustic type of sweetness, but when properly roasted, it's washed Centrals that are deeply and expressively sweet in a truly remarkable way.

Lighter roasts without that much sugar development show more of the malty sweetness, which also expresses itself as graham cracker or wafer cookie. Developing the roast a touch more moves into an intense candy-like sweetness, followed by the more fruited sweetness like that found in cherries and other stone fruits, unique citric and malic fruit tones. Continuing to develop the roast leads to flavors of fruit-infused chocolate, with mild bitterness from caramelization.

Washed Coffee Trying in Chichimes, GuatemalaWashed Coffee Trying in Chichimes, Guatemala

This is the sweetness development path of most coffees, but I feel like washed Centrals showcase this development in the clearest possible way. And of course they can be floral and more exotic fruit too depending on the coffee, but it is this sweetness that is integral and can be counted on for most of the higher grown offers.

The other side of that coin is balance. If this is your goal, you want to develop the roast so that there is as much balance between the acidity and mouthfeel as possible. That balance best showcases the clarity in a well sorted and processed coffee, which in turn allows the sweetness to be the star of the show. Because the acidity can be so brilliant and crystal clear there is always a temptation to roast the coffee light in order to highlight brightness, but there's something to be said for sweetness developed in equal measure, even if that means dialing back the acidity just a bit.

Window on HuehuetenangoWindow on Huehuetenango

In the Stretching out the Roast article and the Cuptoberfest 2013 video I talk about the architecture of a coffee. What I'm referring to is mostly where on the palate you taste/experience the acidity of a coffee. This location has a great impact on how the coffee tastes and feels. If you experience the acidity on the very front of the palate, usually the result of underdevelopment, there is an immediate intensity but then the finish is dry and vapid, not very sweet at all.

If the acidity has been flattened out by over-development then the coffee feels undefined and without architecture. While sweetness may be present in this profile, the lack of any other dimension fails to feature it at its best. My goal with washed Centrals is to develop a roast profile where brightness in only one part of the sum of the coffee's prime attributes, a cup that's sweet from front to back, and a range of cup characteristics across the palate providing depth of field.

What's your approach?

Further Resources:
A Look at our Proyecto Xinabajul in the Huehuetenango Highlands
Blast for the past, Cuptoberfest 2013
What happens when Stretching Out the Roast?
Sure I like acidity, but I love Sweets


by Mike Strumpf and Christopher Schooley, photos by Swiss Water Process and Christopher Schooley

What Makes a Great Decaf - Mike Strumpf - Swiss Water Process

Mike Strumpf - SWPMike Strumpf - SWP

When thinking about how to make an excellent decaffeinated coffee you have to first focus on the coffee before decaffeination. That's right, we said "excellent decaf", a term reserved for coffees you'd be hard-pressed to know are decaf at all. We find these exceptions most with coffees we've sent off for decaffeination ourselves, lots that were selected for high cup quality to begin with. It turns out, the original quality of the green coffee before decaffeination is extremely important, surprise surprise.

In-depth source information on where green coffee comes from is one of the tenants of Coffee Shrub coffees, and custom decaffeination affords us this same insight on non-decaf counterparts too. Deciding whether or not you want traceable information is an important aspect of buying any green coffee, and with decafs, knowing the origin info is very helpful.

We like to think of decaf drinkers as simply "coffee drinkers", in that each person has their own preference for flavor, acidity, body, and all of the other sensory aspects of a coffee. This wasn't top consideration with decafs of the past, flavor being secondary to inexpensive processing. Plus, flavor matters little if the coffee is roasted dark in the end, right? With new much gentler decaf processing technics (such as water processing), volatile compounds are less disturbed, the raw ingredients going into the decaf coffee need to be reconsidered. There is not a best coffee farm or country for decaffeination. The best coffee for decaffeination is the coffee with the flavor profile that you enjoy! Having multiple decaffeinated coffee offerings means you can provide excellent decaffeinated coffee with many different flavor profiles.

The Swiss Water Process provides great clarity of flavor between the "before and after" decaffeination results. In our process, a decaffeinated coffee should taste like the original green coffee and little else. After each decaffeination run, we sample roast and cup the before and after decaffeination samples side by side, focusing primarily on any differences in cup qualities between the two. This clarity means that an exceptional coffee will make an exceptional decaf, and that is what most of us are looking for.

Outside of cup quality, physical bean characteristics can be important in selecting coffees for decaffeination. We analyze all coffees for their moisture content (percentage of the bean that is water), water activity (the state of energy of the water in the bean), and density (mass/volume). These three aspects of green beans are an important trifecta for both roasters and decaffeinators alike, though we might use the information differently. Knowing the relationship between those three physical characteristics can tell us if a green coffee is or is not viable for decaffeination, and as long as a coffee is fresh and sound there are generally not problems.

Roasting and Tasting Decafs Christopher Schooley

Roasting DecafsRoasting Decafs

The classic decaf flavors that most people think of are the overwhelming maltiness, and in the worst cases, wet cardboard, but these flavors are generally the result of the original quality of the coffee itself or the intensity of the decaf processing. When the right coffee is selected and the process is carefully monitored, a good deal of the coffee's volatile compounds that effect characteristics such as flavor and aroma should survive. As Mike says, a really great decaf should resemble the original non-decaf coffee.

The same holds true for how the coffee behaves in the roaster, for the most part. A well processed decaf Ethiopia should behave more or less like a regular Ethiopia, except that the decaffeination process does affect the coffee's density. Because of this you want to be sensitive to how you use your energy input during the roast, especially during the initial drying stage and after the 1st crack has really started to roll so it doesn't get away from you. Basically the more you process a decaf, the more you break it down, and also if a coffee is already in poor shape, you're going to break it down even more. I think a good rule of thumb is to try pulling back on heat as you near 1st snaps to minimize violent bean fracturing, and let the charge carry roast through to your final targeted roast development. On our Probat L-12 fully loaded (23 lb batch size), this means dropping the heat from 75% to 25% about 10 - 20 degrees before first cracks occur. This varies from one roaster to the next and will depend on batch size as well.

The major difference in roasting a decaf are the color change indicators. Color change is a big part of monitoring roast development in regular coffees, but because the decaffeination process alters the color of the raw coffee so drastically, the same color change indicators are no longer present. One of the areas where this is the most problematic is at the very end of the roast. Decafs can appear much darker than what their actual roast levels are, and even begin to sweat some oils as the cellular structure is weaker from decaffeination. Even though a decaf may look dark, it might not actually be as dark as it looks since it started out a darker shade to begin with.

Same Coffee, One Reg One Decaf, Same Roast Level, reallySame Coffee, One Reg One Decaf, Same Roast Level, really

Most other physical and chemical changes are similar in decafs as in regular coffees, such as bean expansion, the 1st and 2nd cracks, as well as aroma indicators. The initial pops of 1st crack may be a little softer, but any well developed roast should have a distinctive finish to 1st crack. The roast aromas during and after the 1st crack are some of the most telling indicators of roast development during this period. You should move past the cereal and bread-like aromas and begin to smell some pungency, almost vinegar-like aromas, but with sweetness to it. Timing past the end of 1st crack is also crucial here, use it along with your aromas to tell you when the coffee has reached your desired roast target. If you roast the regular version of that coffee to an end point of 20 seconds after the end of first crack, then do the same with the decaf version, and adjust from there. Again and Again, great decafs should taste fairly similarly to the regular counterparts

Just because the coffee color is darker and some oils may be present, this doesn't mean that you've engaged in dry distillation or are developing roasty flavors. This is one more reason why when we talk about roast level that the conversation has to be about more than just roast color.

This is more or less a guide to what you can expect from the Swiss Water decafs you buy from us, and elements to consider when roasting. With regard to roast approach, our instructions are on the general side as each roasting machine handles differently, and factors such as batch size will impact roast shaping possibilities. Whatever the case, starting with high quality raw material is one of the best assurances to yielding great results, which for us means starting with a great non-decaf coffee. Add to this equation the gentle decaffeination system of Swiss Water Processing, and you're rewarded with the makings of an excellent decaf cup.


by Dan Wood

1950s Probat B3 - Capable of consistency, this one sees daily use1950s Probat B3 - Capable of consistency, this one sees daily use

We are officially hitting the tail end of the busiest time of year for receiving samples in our cupping lab. It’s no secret that the bulk of our coffees come from Central America and East Africa, and as such, we’ve received more ‘offer’ samples in the past few months than all of the rest of the year combined. This last year in Guatemala alone we cupped over 600 farm samples. Now, to be honest, some of that number was roasted and cupped at origin - maybe 200 total. But the bulk was evaluated right here in our lab in West Oakland. As such, it seems like an appropriate time for us to talk about our process of green coffee evaluation, and why it’s important to have an evaluation program in place.

If you run a roastery, you’re probably well versed in the exchange of coffee samples (often unsolicited!). Whether you’re buying a sample from us, getting ‘spot’ offers from importers, or something direct from farmers, you’re receiving a pretty small amount of coffee that you will theoretically be able to extrapolate enough information regarding quality in order to make a purchasing decision. It can be tricky, especially when the sample is under 300 grams. If it is 300 grams, you generally can get two roasts out of it(on most sample roasting equipment), take a moisture reading (you need 250 grams for most machines), and give it a good visual check for defects. But if the sample is only 100 grams, well, then roasting and cupping will be the two most important tools you use in order to effectively judge your samples.

We use many tools for judging green coffee, but I’m focusing on roasting for this first article. Some of the other evaluation methods are tied to amount, whereas regardless of size, we always roast and cup all our green samples - even when there’s not quite enough for one full batch (because ultimately it’s about cup quality, right?). But even when there is enough for the standard Q grade check (350g), for the sake of efficiency I usually save a thorough visual check for only those coffees I’m considering buying. We get a lot of samples here, and so running every test on each coffee would be much more than a full-time job. But in the end, roasting always happens for every single sample that comes through our doors.

So What IS Sample Roasting?

3-barrel sample roaster, or Friday night at the movies?3-barrel sample roaster, or Friday night at the movies?

For those not totally familiar with sample roasting, the first question is usually “what’s the difference between sample and production roasting?”. One of the main differences is batch size. With sample roasting we’re looking at roasting somewhere in the 100 - 150 grams of green coffee, or enough to make 7 - 10 cups of coffee. With such a small bean mass, roast development happens more rapidly, and so your overall roasting benchmarks, including finish time, will be abbreviated. In general, we shoot for yellowing around 3:30, 1st Crack around 7 - 8 min, and ending the roast anywhere from 8:30 - 10 minutes. This is much shorter than most production roast profiles on multiple KG roasters.

Another difference is that with sample roasting, ‘profiling’ takes a back seat. This also has a lot to do with bean mass. Roasting 100 grams in a steel drum that’s 8” in diameter is very different than roasting 20 LBS in a Probat 12K drum roaster. Heat absorption, convection, conduction, are all greatly affected by the bean bed, the ambient air in the drum, drum material, and on and on.

It’s very difficult, if not impossible to transfer a ‘profile’ you come up with sample roasting to a large production roaster. If we isolate just one of the many factors unique to sample roasting, the small batch size, it becomes apparent that you can’t simply “scale up” a roast technique from a small machine to a large one. The thermodynamics of every aspect are different with a small charge of green coffee in a roast chamber; the turnaround time when the coffee starts to accept heat, the “rate of rise” in temperature in the yellow warming stages of the bean, the bean-to-bean convective and conductive heat transfer, etc.

The only aspect that may be the same are the environmental temperatures of the roast machine, and the set points at which water content in the bean becomes steam, and when the cell matrix of the coffee begins to fracture. What you can do though (and what we do when writing reviews) is get an idea of how a coffee will taste at various roast levels. This is especially useful once you’ve already bought a coffee and are figuring out how it’s best utilized at your shop.

So for us, the use of sample roasting changes with the different type of sample we are evaluating. First it is used to evaluate offer samples by doing our best to roast the coffee(s) to a point where we can effectively judge the quality. And then once we make a purchase, we roast small samples of the landed coffee to different roast levels in order to get a feel for how the coffee tastes at different ends of the roast spectrum.

What Makes a “Good” Sample Roaster?

Quest M3 available here, fully manual, and worthy of handling one sample at a timeQuest M3 available here, fully manual, and worthy of handling one sample at a time

Roasting can be a lot like listening to music, in that if you’re used to playing records with the “loudness” button on, it’s probably best to keep it on when judging fidelity (even though neutral speakers are usually recommended). Similarly, if you’re used to roasting and drinking coffee from a home roaster, and are able to keep roast times within a reasonable range, then it might not make sense to trade out your setup for a fancy multi barrel machine. I’m not saying that if you prefer dark roasted coffee, that’s the best measure to judge a coffee’s quality by. But rather, you can get pretty good at roasting samples using less than ideal (maybe ‘professional’ is a better adjective than ‘ideal’) roasters, and in a lot of cases, it’s enough to get a sample roasting program started. Many shops use home roasting equipment to test samples, and it’s not entirely unheard of to even use a popper!

Finding a roaster that works for you will really depend on your needs, and one major factor to consider is sample volume. How many samples do you plan on inspecting each week? If you’re roasting for a small shop, or only have a few wholesale accounts, maybe a roaster that handles one batch at a time will suffice. You’re probably not looking at too many samples at any one time and shouldn’t expect to spend too much time at the roaster. But if you have several shops, lots of wholesale customers, and perhaps most importantly an ever changing menu, you’re probably evaluating many samples and need a machine that roasts multiple samples at once (and if this is you, I’m sure you already have this). Roasting 100 samples a week on a single barrel machine would be excruciating.

Another factor to consider is the importance of the samples you’re evaluating. Of course, all samples are important when considering a coffee for your business. But how much coffee does that sample represent? It might represent 50 LBS, or a full container (40,000 LBS), two very different ends of the purchase spectrum. And while most fall somewhere in between this huge range, the point is that having a fully manual roaster, and one with a quality build, makes a lot of sense when it comes to precision roasting.

The most precise sample roasters are fully manual. That is, you’re able to control heat, airflow, and sometimes even drum speed. Heat sources are a thing of preference, but we have both electric and gas sample roasters, and while heat transfer is very different, both are more than capable of producing very consistent roasts. Our sample roasters are both 3-barrel roasters, which as I said earlier are necessary in order to handle a large amount of samples in a reasonable amount of time. But there are also manually operated, single-barrel options as well (check out our Quest, electric roaster HERE). And don’t discount home roasting machines. You can get a great home roaster for well under $1K (most are less than half) that will be more than efficient for most small shops.

Consistency is KEY

Cup after cup after cup...dont let roast affect decision making!Cup after cup after cup...dont let roast affect decision making!

So then, for us, the main function of the sample roaster is roast consistency - consistently developing coffees to the same level, just enough to taste as much of that coffee’s ‘potential’ without obfuscating good and bad qualities with flavors of roast. When roasting multiple samples, this becomes increasingly important as roast can be the variable that influences your purchase decision one way or the other. We regularly receive multiple samples from the same micro-region, same varietals, and using the same processing methods. In a case like this, we’re looking for minute differences that ultimately make a coffee preferable over another. This is where roast consistency is very important, as under or over development can hide or highlight certain notes. For example, under development can boost the perceived acidity of a coffee, give off a green/grassy flavor, or lend to paper/drying aspects in a coffee’s finish. So in the case of under development, each of these characteristics is directly tied to roast, and could lead to poor decision making.

Our electric Probat is a very consistent roaster, and while you can’t make sweeping changes in heat, once warmed, it’s fairly easy to maintain roasting benchmarks from one sample to the next. And one benefit to it being a three barrel is we’re able to track the roasts simultaneously, making sure each drum remains in relative sync with it’s neighbor. But there are other ways of tracking consistency than visual cues. Some folks use dataloggers, tracking roast curves and identifying inconsistencies.

From time to time, we will use a very basic manual data logging system to track roast consistency. The first part is determining a percentage of weight loss by simply weighing the batches before and after, and then dividing the pre-weight by roasted weight. I’ll also write down what time the coffee yellows, hits first crack, and is then pulled. This is partly because I want to replicate my roasts from one to the next. But the information is very valuable at the cupping table too. For instance, if we’re cupping several day lot separations from a single producer and one or more roasted samples are out of sync with the rest, we can look at these data sets to see if roast may be influencing our conclusion.

The "Value" in Evaluation

Evaluating the sample is your opportunity to judge a coffee’s potential, isolate “problem” or damaged coffees, or just plain pick the best coffee on your cupping table! So it’s important that you’re able to give each sample the fairest shake possible. The most important part of a sample assessment plan, is having one in the first place. And it’s pretty much a guarantee that sample roasting and cupping will be the tools you use the most, and the two which hold the most weight in purchasing decisions. So as long as you have a roasting machine that you’re comfortable with, can repeatedly achieve a certain roast development on, and that efficiently handles the sample volume, you’re in good shape. The last thing you want is an under utilized beast or over utilized popper! There are other evaluation methods used to measure the more “hidden” enemies of green coffee, like moisture content, water activity, etc...but I’ll save that for the next article.

The pinnacle of achievement in roasting samples is uniformity and repeatability, which are somewhat different than the goals of roasting for consumption; to produce the tastiest cup possible from a given green coffee. But all roasting shares a common thread when it comes to improving your results, that is, tasting. Beyond specific roasting techniques on sundry machines, you improve your results by checking them with a habitualness that might make friends think you have a serious case of OCD. Cross-checking sample roasts with the same coffee roasted on other machines, in particular other small roasters, leads to infinite opportunities to tweak your process and improve.

--Dan Wood


The conflict developing in Ethiopia has been but a footnote in the papers, recently marked by a horrific stampede at a political rally and the declaration of a 6 month national "state of emergency" on October 10 2016. Beyond the specific interest in the wonderful coffees we source from Ethiopia, there's a broader concern here. How can we enjoy a coffee when there is conflict behind the production of the crop?

The dramatic militarized situation has been long in the making, and as a visitor to Ethiopia I cannot pretend to understand all of the history and it's complexities. While Ethiopia has a booming economy and evidence of many development projects can be seen all over the capital of Addis Ababa, development in the faraway rural areas in much more modest. While Addis boasts a new light rail line, rural regions are lucky to have their roads re-graded or potholes fixed. Development seems intricately linked to the interests of investors. Powerful foreign investment comes from Saudi Arabia (mainly by billionare Mohammed al-Amoudi) and, to a much greater extent in recent years, China. Nigeria and India invest extensively in projects here, as well as a host of others including wealthy Ethiopians from the global diaspora.

Large tracks of prime arable land are dedicated to projects by these foreign investor groups, and some feel the land grants are giveaways without fair compensation benefiting local populations, aside from some job creation. In fact, student demonstrations around the country have centered around this issue; what is seen as a government land-grab. This was evidenced by the move to annex lands surrounding Addis Ababa into the domain of the capital, and event that escalating protest activities.

A root cause is the fact that Ethiopia is a confederation of many old kingdoms which represented the various ethnic groups of the region, united under one Empire until 1974, yet it has been dominated by one group. The Tigray minority makes up only 7% of the population but by some estimates controls over 70% of the economy, and over 95% of top military/security positions of power. While the constitution is designed for power-sharing and autonomy for the ethnic zones of the country, this is not the de facto situation. The coalition in power since 1991 includes 4 parties representing different ethnicities (including the Oromo and Amhara) but it is said the TPLF (Tigray) party possesses all the influence. And it seems the other parties in the ruling group lack legitimacy amongst their own people who are on the protest lines, as they are seen as impotent to enact the agendas of those they represent.

Local protest sign - Lake Merritt, OaklandLocal protest sign - Lake Merritt, Oakland

Oromo and Amhara peoples constitute over 70% of the Ethiopian population, but travel through these areas is quite different than the developed urban centers. It's more than just an urban-rural divide, and in fact when there are tensions in the country, or a key meeting is held in Addis, I have experienced an intentional shut-down of the internet in the rural areas I have been traveling. This type of heavy-handed, autocratic control is typical of Ethiopia, where telecommunications and other critical industries are state controlled (which means Tigray-controlled).

The coffee industry in the country expresses such a divide. We focus almost entirely on coffee areas farmer by the Oromo people. That's not surprising as they are by far the dominant group in the Western areas and the South where we source our coffee. There are many smaller ethnic groups that farm coffee that we buy as well, the Sidama people, Harare, Welayta, Kafina, Guji, (and others which are subgroups of the Oromo or Sidama). But the trade in Addis is not conducted by these people, but by a more elite clique, those with connections secure needed bank financing. I don't claim to understand the nuances here, but there are deep levels of corruption in Ethiopia with corresponding deep levels of mistrust. While evidence of development is all around, it seems focused to benefit urban elites. While educational opportunities have expanded, those with degrees find they lack political connections to land appropriate jobs. While Ethiopia takes in enormous levels of food aid and other funds from donor groups, it also ropes off valuable land for food farming to connected locals or foreign firms.

All of this is why the crossed arm symbol of protest by Feyisa Lilesa at the Olympics was such a charged gesture. What we hope to see is a meaningful dialogue open up between the government and protestors, but for now, travel in Ethiopia is a greater risk, and ultimately the farmers will suffer under the limitations imposed by the state of heightened security. What will it take to defuse this tense situation?


Panorama of the back half of our new warehousePanorama of the back half of our new warehouse

 

As most of you already know, Coffee Shrub and Sweet Maria's moved to our new warehouse all of last week. The move's gone well, and we're working to shore things up this week. In reality, we'll likely be putting on the "final touches" for weeks to come, but we expect our order fulfillment to be back up to full capacity middle of the week (Wednesday August 31).

This is the first move for Shrub, but for Sweet Maria's, this is the fourth relocation in 17 years. A few years after opening shop in an office space in Columbus, OH, selling small bags of green coffee and brewing cups for the occasional passerby, Sweet Maria's packed up and headed to the sunny West Coast landing in a small warehouse space in Emeryville, CA. We soon outgrew that location, picking up and moving operations to an improved 7000 square foot space in lovely West Oakland where we've spent the last 8 years. We had a good run at location 3.0, where Shrub was born 7 years ago. But if inventory is any indication of growth, we've been bursting at the seem for some time now, and so this move does a lot to relieve the pressure.

Loading dock deliveries to the right, Shrub walk-ins to the leftLoading dock deliveries to the right, Shrub walk-ins to the left

At 15,000 square feet, our new Adeline Street location affords us much more room for green coffee and product storage, as well as additional spaces for hosting demos and cup tasting in the near future. And just as important, we're able to set up the warehouse workflow around working smarter, with less requirement for the strenuous physical labor that comes with constantly trying to fit a boulder into a teacup (or perhaps demitasse is more appropriate!).

To illustrate, last year we purchased and processed 50+ full container loads of coffee in a warehouse that can hold about 1.5 containers max. This meant many, many trips to an offsite storage facility, accompanied by much physical labor organizing 60+ kg bags of coffees in order to have backstock on hand for all of the coffees we sell. Doubling our square footage allows us to change our footprint of how we store coffee, actually quadrupling our storage capacity. Of equal importance is the addition of our very first loading dock, which means we can increase our use of forklifts and other machinery for moving coffee in and out of our warehouse, further decreasing our reliance on the literal backs of employees. We value our bodies, and so lowering the lifting requirements is a huge plus!

Marcos tests out our new filling stationsMarcos tests out our new filling stations

We didn't build the walls or pour the concrete (well, not all of them at least), but just about everything else has been completely DIY. From dealing with City permits and coordinating building plans on the part of Maria (no small feat!), to Tom's tiling the bathrooms, and to every single employee here taking part in moving, cleaning, and building the infrastructure (which is a HUGE job), this has been a collaborative effort with little to no outside help. This is very much in the spirit of both Sweet Maria's and Shrub as businesses.

It goes without saying that we are excited for this move, and all the possibilities and promise that comes with it. More than anyone, we want to be moved and completely set up today....last week even. But these things take time, this milestone move now 17 years in the making. So for now, I have to get back to unloading a box truck full of coffee, mylar bags, and packing equipment. One step closer to the finish line. -Dan


Rwanda + Burundi = Espresso PerfectionRwanda + Burundi = Espresso Perfection

When considering "African coffees", I tend to think of exotic flavor profiles and pronounced acidity, and rightfully so. So many of coffee's crown jewels are produced in equatorial regions in East Africa and near the Great Horn, where Coffea Arabica was born, so to speak. These coffees shine in light roasting, often the featured cup at a slow bar, and have changed the minds of so many coffee drinkers who once thought that all coffees taste the same.

Rwanda and Burundi stand out, due in part to the massive plantings of the bourbon cultivar. Brought to the region by missionaries in the 19th C, bourbon is known for it syrupy sweetness and nuanced cup that comes with growing in the higher elevations. We find that the coffees from both countries produce an extremely diverse range of cup flavors: from the heady floral and spice characteristics of competition-level lots, to the dense (almost "chewy") raw sugar sweetness that we think of as much more akin to our best Central American coffees.

And while often the center piece of a café brew bar, Rwanda and Burundi coffees aren't considered nearly as often as they should for espresso application. Bourbon beans can be quite dense, making them a more than viable option for dark roasting, and also espresso. They produce compact sweetness, along with moderate floral and acidity levels, and more are more often than not are a near perfect single origin espresso option in our opinion.

For this week's production roasting, we chose Rwanda Nyamasheke Mutovu and Burundi Murambi Rubanda as our coffees for espresso (if you didn't already know, we do offer a coffee subscription service every other week). Our approach in the roaster was to finish on the inside edge of 2nd snaps, no oil present on the bean exterior. As you can see in our roast graphs, we tried for a gradual ramp-up in heat, slightly extending the time between the beginnings of first snaps and finish in order to tone down acidity, thus producing a much more rounded cup profile.

In fact, the goal was to produce a roast that's works well as both espresso and brewed coffee, which these do, especially for those who are partial to the bittersweetness that comes with deeper roast tone. Both coffees are intensely sweet at this roast level, which I'd say is dead center on the Full City roast spectrum. When brewed as coffee, a smokey cacao-nib flavor is one of the dominant characteristics in both coffees, but with a counterbalancing sweetness, and subtle fruit hints as the cup cools. Acidity is compromised with a stretched roast, which is something to keep in mind when deciding on your own roast approach. But our intention was to mute the acidity to keep from puckering brightness that often comes with African SO espresso.

We don't have fancy logging software, and so some pertinant info is missing above. Other relavent data: 1st crack @ 11:55, finish @ 15 minutes, with 14.8% weight loss

Burundi Murambi Rubanda: It always takes a few shots to get the grind dialed in, and we like to taste them all, for better or for worse. My first really tasty shot was with 22 grams of coffee going in, and 18 grams coming out in roughly 20 seconds. Even at this fast extraction the bittersweetness is so intense. Up front flavors are like Hershey syrup, with a lemon juice tartness that rings loud, but is cut short by the ushering in of roast tone, a flavor that plays out like roasted cacao nibs. The second shot was quite different, 17.5 grams of coffee in, 28 second extraction, and 29 grams of liquid coming out. The acidity is much more integrated into the overall profile, and the bittersweet chocolate tones are up front, and linger (we noted a "rooty" flavor in the long aftertaste). We did one last pass with a slightly tighter grind, 18 grams of coffee in, and 22 grams out over the course of 32 seconds. This is the one for me: sweetness fully realized, a lemonade-like top note, and extremely viscous mouthfeel.

Other relavent data: 1st crack @ 11:45, finish @ 15 minutes/425 F (forgot to plot that final point!), with 14.6% weight loss

Rwanda Nyamasheke Mutovu: Having good luck with our final Burundi shot, we decided to use the same parameters from the get go: 17.5 grams in, 24 grams out, and 32 second extraction. This is a slightly brighter coffee, from lemon juice tartness to a rindy orange peel bittering quality. The sweetness is moderate but convincing in this extraction, and a counterbalance to a Baker's cocoa powder that adds to a touch more bittering in the finish. Adding just a hair more coffee on a second pass, but same time and liquid out, pushed the sweetness as well as acidity, culminating in a shot that reminded me of dark chocolate covered lemon drops. I pick up on some spice and fresh herb-like accents too in the finish, that give off an impression of a hoppy ale.

Between these two origins, we currently have three coffees that are well worth their weight in espresso. Staying north of 2nd snaps, you can expect profiles to follow a similar construct as the ones in this review. See the full list of HERE (we actually have an 8 lb Rwanda/Burundi sampler on our sister site, Sweet Maria's, if you'd like to check out a wider representation of coffees from the regions - HERE).

It's worth adding that the main reason cafes have trepidation around these two origins is the potato defect, which like all other coffee flavor compounds, is intensified in espresso extraction. Thankfully, the tide seems to be shifting a bit. Tom was at Blue Bottle recently, and noticed that they were serving a Rwanda as espresso. To us their reasoning is sound, and right in line with our feelings on the matter as well: Burundi and Rwanda coffees are just too damn good to let an infrequent potato cup negate these origins altogether. -Dan