Corvus Log

When Single Isn’t Everything It’s Cracked-Up to Be

by Doug Stone |


Many craft-focused espresso bars “only serve double-espressos” or explain that “we pull all of our shots in pairs” when a customer orders a single or triple shot beverage. We essentially keep one double-shot sized extraction recipe dialed in. But why? Are we just being lazy? Not exactly. This is because our focus is to make the espresso taste the very best that we can, and we would have to be constantly adjusting the grind to switch back and forth between recipes of varying size on one espresso grinder.

But what if we had a separate grinder for single shots? It turns out that just like the laws of the universe are altered in sub-atomic particles or when something is traveling close to the speed of light we also start running into special problems in coffee when we reach extremes. Trying to brew a delicious 15 gram single shot from 6 grams of ground coffee will show this.

The diameter of a portafilter’s brew basket doesn’t shrink proportionally with different doses. Even if you have a shallower basket for single shots, the bed of coffee becomes more pancake-shaped, is prone to channeling, and is difficult to hit appropriate shot-times due to drastically decreased resistance. Less coffee is in the way of the water after all. You have trouble hitting that 25 to 30 second benchmark which gives the water enough time to grab all of that flavor and body you want as it passes through the coffee. As a result, single shots are often much lighter bodied and acidic tasting, especially with modern coffee roasts.

We can attempt to grind finer to make up for this quickening effect, but as with everything in life there is a diminishing marginal return on grinding coffee finer for espresso. In fact, a point comes when the coffee is so fine and flour-like that the water can no longer pass through the coffee bed evenly because the spaces between grounds are just too tiny. Once again this “choking” effect causes flavor and body to be left behind.

It’s not that single shots can’t be executed decently every so often, but in a world where pulling a perfect shot can be elusive with even the best conditions, focusing on one recipe that works best sets us up for success!

Costa Rica: A vision for the future & sustainability

by Phil Goodlaxson |

Costa Rica is an exciting place to visit for coffee. The natural beauty is amazing. Spectacular flora and birds are everywhere you look once you exit San Juan. For me, the real treasure is the model which Costa Rica has for sustainability. Often there is a lack of clarity around the concept of sustainability in coffee. We roasters all come up with our own definition and individual measures for success around sustainability. This is great most of the time because of the multi-faceted nature of this issue. It encompasses issues around social justice, the environment, quality, and government. But in Costa Rica there is a model of sustainability which demonstrates success in indisputable ways.


The first is in relation to the environment. Most of Costa Rica’s income comes from Eco-related tourism, and they have many laws in place to protect this natural resource. The most significant to coffee production is protections for their water. There are strict regulations on the quality of water that agriculture and industry can re-introduce into the environment as waste. Coffee farmers need to filter all their waste, which is very expensive if you use a lot of water. As a result, many farmers have begun specializing in honey and naturally processed coffee, which requires less water than fully washed coffee. It’s a win-win response to environmental concerns because Costa Rica has become known for some of the highest quality honey and natural coffees anywhere in the world. Prices have risen as demand has gone up, and farmers are protecting the source of their livelihood- the environment- at the same time.


My second observation in Costa Rica this year is the prevalence of micro-mills. Around the world it is common for small farmers (producing 1-2 containers per year or less) to have wet milling capabilities at their farm; that is, taking coffee from the fruit to the dried seed. But is is uncommon to see smaller farms with dry milling capabilities; taking the dried seed and sorting for defects, uniform bean size, and uniform density. In Costa Rica we visited many farmers who have dry milling capability right at the farm instead of taking their dried coffee to larger towns where dry mills are huge operations. Often these farmers are also milling coffee for their neighboring farmers who don’t have dry mills. There are a couple of really sustainable results to this practice. The first is that having control over the entire production can facilitate rapid quality improvements as well as relationship sourcing between farmers and roasters. This increases the amount of value kept at the farm level, which is one of the irreplaceable links in the supply chain of coffee .

The other element of sustainability that comes out of these micro-mills is that it provides a solution for the shift away from agriculture to urban lifestyles within younger generations of coffee families. All countries follow this shift from agrarian to industrial economies as they become more prosperous, and it’s not something that we could or should try to prevent for the sake of maintaining quality coffee production. So instead of ignoring this inevitable problem we need a solution which allows for regional consolidation. These dry mills, being at the farm level, are spread throughout growing regions and are relationally tied into existing growing communities. Farmers who are focused on a long term, multi-generational coffee business put in a dry mill to increase quality, lower costs, add efficiency, and so on. They begin milling coffee for their neighbors, who farm essentially the same soil, in the same climate, and in an overall similar terroir as the micro-mill owner’s farm. As I see it, this creates opportunity for up an easy transition to consolidate nearby quality focused farms if younger generations leave. Their neighbors already are processing and selling their coffee, and understand the environment around them. Many countries only have dry mills in large urban centers, and if families move away from agrarian livelihoods, there is no real sustainability succession in place. Costa Rican micro mills give me hope that there is a solution to this problem not only here but potentially in other areas of the world.


Costa Rica has many sustainability practices in place that I take as a beacon of hope in what often can seem like a bleak outlook at origin. One of the most uplifting things to see is the vision of a successful coffee farmer which is alive in Costa Rica. In order for the specialty coffee industry to continue to grow and maintain quality farmers need to share in the prosperity we are seeing here in consuming countries. The goal can’t be to increase livelihoods from $2,000 to $4,000 per year (which would be “doubling average farmer income in Ethiopia”). We need to shoot higher. We need to see the future as one in which coffee farmers are achieving the same level of success as vintners in Napa Valley. Costa Rica brings this vision to life and paints a picture of what this can look like. Many of the farmers we visited have comfortable villas, very nice cupping labs, and are moving towards the same level of success as their counterparts in wine, spirits, and other farm level producers in craft industries.



These things; ownership of the supply chain, response to environmental concerns, a focus on quality, and a model of succession and success make me hopeful for the future of the coffee producer. It feels like an uphill fight some days, and it’s a breath of fresh air to get a glimpse of a positive future!

The case for Flat Bottom Brewers

by Doug Stone |


Flat Bottomed Brews, You Make the Coffee World Go Round!

“Batch brewers are just so inconsistent.” -No Barista Ever

Single cup manual brews are sexy, but you just can’t deny the consistency of larger batches of coffee. With increased batch size comes an increased margin for error. Put it this way: If you’re ten grams over or under for a 200 gram dose, you’ll detect way less of a difference than if you were ten grams off of a 20 gram dose. The same thing is true of other factors; a few seconds longer brew time for a V60 makes a big difference when the whole brew lasts two and a half minutes compared an eight minute gallon-sized brew.

But what about the middle ground? I’m thinking of manual brews at home for several friends. There are only few practical options. For one, you can make one giant French press, of which I am a fan. But not everyone likes to chew their coffee. Alternatively, you could make an aeropress or a V60 for everyone. Have fun grinding coffee and pouring water for the next twenty minutes while everyone else enjoys breakfast!

Then, there are a few pour-over companies who have made it possible to do bigger doses all at once, the main one that comes to mind being Chemex. But the problem I have with the Chemex is that the cone comes to a real point and if you don’t have a quality grinder it can flow at a very slow rate. The water stops dripping and leaves you scratching your head thinking you’ve defied gravity somehow. Think about it—how many big batch brewers have you seen with a traffic cone-sized filter basket? No, they all have flat bottoms. And don’t get clogged. And taste the same every time.

I recently got my hands on a Stagg [XF] pour-over brewer by Fellow. It has tall straight sides that form a cylinder and the filter looks just like a skinny version of a big basket filter. I love designs like this—the Kalita Wave is another one—for all the same reasons why nobody stresses out about brewing coffee on big batch brewers. A 24-ounce batch of coffee would take ten minutes or more to finish brewing on a Chemex (I would know, I’ve done it a time or two) while on the Stagg, it completed in about four and a half minutes. It’s so handy that I’m thinking of incorporating this style in our own brew bar service here at the roastery. 

And because the brew bed is flatter, there’s less technique required for the bloom and throughout the pouring process, even with single-dose brews. The flat-bottoms of the pour-over world are user friendly, consistent, and can make enough coffee for your brunch guests without tying you up for a half hour at the kettle. Count me in!

A quick note on Ethiopia

by Phil Goodlaxson |

With our newest Ethiopian from Kayon Mountain in I wanted to drop a note about my experiences in Ethiopia. A lot of our favorite coffees come from Ethiopia, and I would say that is true for 90% of coffee roasters. They're exotic and unique, unlike any other coffees in the world. Generally speaking, quality coffee is synonymous with really knowledgeable farmers and advanced agronomy and processing techniques. Visiting Ethiopia really shocked this idea, and drove home the importance of soil. 


Coffee evolved in Ethiopia, and all coffee comes from strains in this region. Visiting farms here I was really surprised to see how much of the flavors I've come to love in Ethiopian coffee are a result mainly of this ideal climate ad soil. Many of the farms had very little knowledge of agronomy practices compared to Latin American farmers. They weren't pruning trees systematically, planting mainly government approved varieties, and doing little nutrition management. But their coffee was fantastic! The buyer from Sweden who I was traveling with made the comment that if we would take a Colombian coffee farmer and give them soil like this, the results could be incredible!


So, the potential in Ethiopia is still enormous. Farmers are starting to hire agronomists, keep better track of coffee as it moves from the field through processing (micro-lot work), and understand the importance and benefits of practices like pruning and spacing trees appropriately. Ethiopians as a general rule are an unusually friendly group of people, good natured and open hearted. The coffee is fantastic already. Working with farmers like Ismal at Kayon Mountain and seeing him adapting more micro-lot practices; tracing coffee in individual plots picked on specific days through the entire process gets me excited about how much better the coffee here can get!


The Flash

by Doug Stone |


The warm weather is upon us and with it iced coffee season! It’s no secret that we love cold brew here at Corvus; we have five different kinds in bottles alone not including the many Kyoto cold brews you can try at our DTC location. But those all take hours to make, and if I’m outside by the pool craving iced coffee, I don’t always want to wait until sundown to drink it! In that case, I’ll use a method we refer to simply as “flash brew” in which we use hot water to brew coffee directly onto ice. It makes a really sweet cup of iced coffee in mere minutes rather than waiting hours for immersion-style cold brew.


I enjoy using the chemex for this for a couple of reasons. For one, it’s big enough to hold a few cups so I don’t have to keep brewing non-stop, and it’s also its own decanter which is pretty handy, too.

Here’s where I get hung up when it comes to recipe creation for flash brew. When making hot coffee, the cup is entirely made up of water that passes through the bed of grounds. In the case of flash brew, some of the the water is from melted ice that was not used to brew the coffee. But it still affects the final strength which, by the way, is constantly changing as the ice melts. I’m a bit of a numbers nerd with my recipes, so this melting ice concept had me chasing my tail.

I was using our Boloya from Ethiopia which is always delicious, so how hard could it be? I tried several things: Increasing the ground coffee dose by 50%, 100%, coarse grind, fine grind, I even tried brewing the coffee at a super strong concentration and adding the ice afterward. Nothing seemed to be working, and that was when I learned my lesson. I was over-thinking it. So, I finally tried something simple: Take half of the brew water away and replace it with ice in the decanter. Using half of the normal amount of water to brew coffee would make me expect an under-extracted sour tasting cup that is too strong. But what resulted was sweet, bright, and balanced. 

I always say this in the coffee classes I teach: The numbers don’t mean anything if it doesn’t taste good. And just when you think you know a thing, coffee will humble you. I guess that’s just the magic of it all.


Here’s the exact recipe I used:

21 grams of Ethiopia Boloya ground medium

160 grams ice in the bottom of the chemex

176 grams of boiling water to brew


If you don’t have a chemex, use my trainer code “flashbrew" for 10% off online or in store!

limited to 20 customers