Craft or Science?
I am very much a scientist by training and inclination and my creative outlets tend to be practical. I enjoy fine art but have no drive to pick up a brush or a pencil. I particularly like sculpture but I am as much intrigued by the creative processes that brought a human being to envision an abstract object as I am by the object itself. I know the same process is just not happening inside my own head.
Give me a superb fresh fish, an excellent piece of meat or some fabulous vegetables and I am positively inspired to create something. More to the point, an interesting new coffee drives me to experiment: changing roast parameters, tweaking the roast temperature or the way the temperature rises, extending or contracting the pre- and post- first crack development times, roasting to different degrees of darkness, looking at rates of water loss… Everything gets logged and analysed and each combination is assessed against cupping properties and the results with different brewing methods.
All very scientific and intended to help me find the optimum roast, but does it actually work? The fact is, the results are very subjective. With our fine coffees, we always keep our roast parameters within the zone that brings out the best flavours, but that zone can be quite broad – from city roast to light French perhaps. Sometimes I can’t honestly say that one roast profile is ‘better’ than another, just that it's different and perhaps equally enjoyable. Some coffees are sensitive to levels of acidity and taste better with more or less of it, some need adequate body development or a touch of sweetness to bring out their best. Others just seem to cope perfectly well with whatever I throw at them. From a customer perspective, educated coffee drinkers are looking for flavours that others might not like. My experimentation is therefore useful but is at best a guide.
The unusual design of our roaster makes roasting a very sensory thing. Unlike with an enclosed drum roaster, it is all happening right in front of me. A glance says exactly where we are in the roast cycle. My nose tracks the transformation from earthy green bean, the vegetable woodiness as they start to tan, through to the time when the distinctive aromas of roasting coffee start to emerge. First impressions are almost chemical, then new notes gradually appear in succession until I hear the tentative crack of the first expanding bean. From then on it is a riot of sound and scents as the coffee takes life.
How far do I take the roast? My bean probe and profiles tell me one thing: my nose says take it a little further this time. I drop the temperature a fraction to extend the roast, until I catch the faintest hint of smoke and that’s it. The beans are dumped into the cooler, dragging the heat off them in seconds and essentially freezing the roast at the point of completion. After less than a minute the aroma has dropped away and it is time to assess the colour, the evenness of the development, to record the results against my target - back to science.
So is roasting coffee a craft or a science? Well clearly both have a part to play. I need my science to explore the parameters and even more to ensure I can consistently achieve the same results. But of one thing I’m certain. Just leave it to my senses and I’ll roast you a damn fine coffee.