Roasting for Ratio

Written for and seen in Fresh Cup Magazine's February 2016 EditionAs roasters, we tend to think of the act of roasting as an isolated and pure event. We talk in terms of roast profile, development time, end temperature, final color, weight loss, and other particulars of our craft. However, our roasting does not exist in a vacuum. At the end of the day, there are numerous things that play a roll in everyone’s unique approach to roasting coffee.One variable is the ratio of coffee to water we use when evaluating our work. For anyone who has taken a brewing class or spent a lot of time messing with a refractometer or total dissolved solids meter, it makes total sense that small changes in this ratio can make large differences in the way the coffee tastes. However, something you may not have thought about is that the ratio you use when you cup or brew for quality control influences the way you roast your coffee. Whatever the ratio, it greatly affects your soluble concentration and soluble yield, which in turn affects the expression of the attributes of the coffee, including body, acidity, sweetness, and flavor, to name a few. This in turn affects the changes you make to your roast profile since we adjust them to create the particular flavors we seek from the coffee.In very general terms, the more volatile a compound is, and the lower its molecular weight, the faster it finds its way into the water during brewing. The heavier the molecular weight, the longer it takes for the compounds to come out into the water. The way that the Coffee Taster’s Flavor Wheel is set up (with regard to the aroma section) is from lower molecular weight to higher molecular weight (lighter colors are lower in molecular weight, and darker heavier). This means that the way coffee’s flavor tends to evolve is from enzymatic-like flavors (think fruity, floral, and herbaceous tones) to sugar browning–like flavors (caramel, nutty, chocolate) to dry distillation-like flavors (carbony, spicey, and resinous). “While there is some of every type of aromatic compound in the water at each stage of the brew, the arrival of ever greater concentrations of heavier compounds tends to move as described above.” Therefore, a coffee with eighteen percent soluble yield tends to emphasize the enzymatic category, twenty percent the sugar-browning category, and closer to twenty-two percent the dry distillation flavors.The reality of our experience as roasters is that we always and can only really work off the roasted and brewed product. We can never truly taste the green, we are always tasting the influence of roast. Likewise, we can never truly taste the roast without the influence of the brew. For our businesses this means a few things.First of all, you have to tell people, especially wholesale clients you are courting, your ideal coffee-to-water ratio when you leave them samples. It is so common for a café owner, not knowing the brewing parameters used by the roaster, to prepare a coffee and walk away unimpressed, but then be bowled over whenever visiting one of the roastery’s cafés. This is because we roast our coffee to hit its potential (or what we consider its potential to be) when using a particular coffee to water ratio, and if the people brewing your coffee are unaware of that ratio, they will not have the proper experience.As such, I recommend including something about the coffee to water ratio on your packaging (both for sampling and retail), or offering an informational card to potential wholesale clients when you leave samples. Also, make it a point to have conversations about their brewing parameters whenever you get feedback on your coffee.Secondly, this means that you too may have to make a choice. This may mean that you change your production cupping and quality-control brewing procedures to reflect the standards you have out in the field so you have an accurate understanding of how people are tasting your coffee. Or it may mean you take the ratio you have in the lab and move it out to the brewers, and bring the lab experience to your customers.Years ago, we were noticing a drastic difference between the way things tasted when we checked the coffee or did a production cupping, and the way it tasted out of our batch brewers. We frequently do a 15.5:1 ratio when brewing in our lab for production cupping and manual brewing (the reason for which is another story). But the common batch-brew recipe of seven ounces of coffee to a gallon of water is actually 19:1. The 19:1 ratio passes through the ideal window for brewing between 19.5% and 22% soluble yield, where as the 15.5:1 passes through the ideal brewing window between 18% and 19%. This means they fundamentally emphasize different groups of flavors in the coffee. I wasn’t roasting coffee to be its best at the ratio we brewed it at for our customers.So I felt that we had to make a choice, namely to bring all our brewing parameters—especially with regard to coffee-to-water ratio—into alignment. This meant increasing the amount of coffee we use on the batch brewers in our café and at events to showcase what we considered the optimum flavor profile of our coffees. As we brought the coffee to water ratios into alignment, we saw the flavor change into a much closer facsimile of what we were tasting week after week on our production cupping table. This meant that whatever I taste in my lab, or on my cupping table is a very close representation (and much closer than it was originally) of what my customer is experiencing when they drink our coffee.The challenge then to the reader is to not only be aware of the influence of brewing on the flavor of your coffee, but to take control. It is up to you to be thoughtful and planned when it comes to how you are brewing coffee in your lab, how you brew in your cafes and wholesale accounts, and how you educate your customers. Because, at the end of the day, it is all about the flavor of the coffee.