Today I opened a new lot of Yemen Mocha Sanani. Whenever a new lot of any coffee is opened, it is necessary to determine the best way to roast that coffee. Coffee is an agricultural product that varies from season to season, farm to farm, and even among different lots of coffee from the same farm and season. The best method of roasting a particular coffee will change over time.
Each coffee origin, be that a broad geographic region, a country of origin, a DCA, a cooperative, or a farm produces a coffee of a particular character with the more specific origins allowing for more specific expectations and fewer exceptions. Some take the opinion that it is the responsibility of the roaster to make coffees from a particular origin taste like coffee from that particular origin. Taken too far, this is absurd. A coffee from a particular country ought to taste like a coffee from that country, but any generally desireable characteristic that can distinguish a particular coffee from the rest of the coffee grown in that country should not be ignored. It is only fair to mention that there are roasteries that disagree with this point and aim for maximum consistency from one season to the next. I think that this results in a mediocre offering weighted heavily in blends, but there unfortunately is a place in the market for coffees that are good, but unremarkable. There are is also a place in the market for coffees that are simply awful, but I have very little contact with these poor coffees or the people producing them and so I will not say more of them today.
No matter what the goal of the roaster with regards to a new coffee, it is still necessary to decide on the best way or ways to roast that coffee. Simply roasting a new lot of coffee in the same way as the old lot was might occasionally work, but often it does not. It is necessary to try several roasts of a coffee before deciding how to roast it. I usually have some idea of how a new coffee might best be roasted, so I'll pull samples in a range that starts a little lighter than I would expect to find a good coffee and ends a little darker than I would expect to find a good coffee. I then try each of these samples. Sometimes, as was the case with today's Yemen, there is one sample that is obviously correct. Other times, I may need to perform another sample roast, pulling samples in a narrower range to find the right roast. In other cases I'll suspect that finding the right roast requires another sample roast that varies from the first in some way such as airflow pattern or time spent in a particular temperature range.
Samples are tried by a technique known as cupping. A certain amount of each sample is ground into a cup and a specific volume of hot water is poured over these grounds. A cap of coffee grounds floats at the top of each cup. The cupper then uses a spoon to break this cap while simultaneously smelling the sample to get a sense of the aroma. Some prefer to do this by pressing the back of the spoon through the cap. Others find they can get a more complete sense of the aroma by taking a spoon of grounds and smelling that before completely breaking the cap. Once this has been done for each sample, most of the grounds will be at the bottom of the cups. Excess grounds left on the surface are removed. Now the samples are ready to taste. This is done by taking a spoon of a sample and slurping it so that coffee is sprayed throughout the mouth. Some swallow the samples in order to gain a better appreciation of the aftertaste. Others prefer to spit the samples out.
In the case of the new Yemen Mocha Sanani, I pulled eight samples and found that the fifth one tasted just as I expect good Yemeni coffee to taste. In this case, that means an end temperature of 445 degrees, a little darker than the previous lot but still very much a medium roast. The coffee starts out sweet and winey, but as it cools it becomes dry and nutty.