This week, Tom asks: have you tried more than two coffees at a time in a blend? do you roast the individual coffee type separately and then blend? Or do you roast the coffee beans together as a blend? As always, I love receiving questions! And this dovetails perfectly with the recent introduction of parameters. In classic fashion, before we get to these specific questions, let us chart the history of blending coffee.

It is difficult to find well-documented sources but the lore of blends starts with the ‘mocha-java’ blend. One of the very first countries to export coffee was Yemen. Its Al-Makha or Mocha port in the Red Sea operated as the hub to send crops to Europe. While in the then-Dutch occupied, Indonesia, commercial farming propagated throughout the Java area. The fruit-forward Yemenis roasts worked as a perfect counterpoint to the earthy and spicy Java. Akin to many things in the industry, these myths emerge as marketing tools for exploitative green buying and the dreaded dark roast.

Second wave coffee brings the rise of the signature blend. With an expanding market and the relative scarcity of quality green, companies like Folgers and Maxwell House began roasting large quantities of robusta. Blending is perfect for diluting its harsh flavours. Using past crop or beans with defects as smaller components became a way to generate larger profit margins. Third wave refocus the conversation towards traceability, which meant rejecting these amorphous, cheap blends. At most specialty shops today there is a ubiquity of single-origin or single-estate espresso.

And yet, Cut has blends? The why is simple: blends are delicious for espresso. With that early Mocha-Java incarnation, the whole is better than the individual parts. Due to the dynamics of pressurized extraction, a short time frame, and ratio of bean to water, espresso will amplify taste notes. Delicate lemon becomes a harsh bite of peel or soft florals blow out into exaggerated sharp tartness. An easy fix is rounding out these strong acidic tastes with sweetness and bitterness. The strength of the blend comes through the structuring and building of complex flavours. Like baking or cooking, a much more complete profile emerges through the layering of different but complementary notes.

Onto Tom’s questions! Yes, we have had blends with three components. When I took over roasting in 2014, Butter Knife was a 40% Brazil, 40% El Salvador, and 20% Indonesia. The logic was right from a flavour point of view with Brazil providing creamy peanut, the El Salvador adding orange citrus and the Indonesia grounding it with an earthy base. Yet, it was a difficult to dial-in. In trying to grapple and solve this problem, I garnered one of my fist key lessons in roasting: solubility!

Making coffee relies on moving the volatile compounds from the grounds into the water. Solubility measures those elements that dissolve and is dependent on two factors: roast development and grind particle size. The longer and darker you roast, the more you break down the porous structure of a bean, increasing both development and solubility. Yet, if the goal in roasting is to showcase the innate flavours tied to origin, you need to roast lighter, which reduces solubility. Accordingly, we suggest different grind settings that correspond to each coffee’s roast profile (and by extension, its unique level of solubility).

Creating tasty blends is a game of profiling to bring out the sweetness of origin but also aligning an overall level of solubility. The problem with the three-part blend at Cut was in making the parts individually delicious, the development varied widely. And by losing cohesive solubility, chaos reigns! You could pull a shot of 30/30/40 and it extracts one way but the next grind gives you 60/30/10 and a whole new mix of solubility. It creates an under-extracted and over-extracted jumble. The solution was to make Butter Knife a two-part blend and start sourcing coffees that work better together by requiring similar levels of development.

Onto the second question! In profiling building, each type of coffee gets a unique application of heat, air, time, and pressure. So we roast the parts separately, sort them, weight them out to formula, and then use a cereal mixer to try to get the batch as unified as possible. It might sound like a lot of work compared to single origin espresso, but again, the opportunity to create these complex but balanced pairings is worth it. I think a great number of people in the industry slag on blends because they often don’t taste great. BUT that is due to problems in roasting, not the act of blending itself. I remain very wary of commercial blends with no origin information and shy away from any signature blends titled after roast degree but will never turn down a well-sourced, well-roasted blend – it can be a harmonious chorus in a cup!