Cupping – An integral part of one’s journey learning how to roast coffee
All coffees have a “sweet spot”; some have two. The sweet spot is the degree of roast that yields the coffee flavor that is most appropriate for the purpose required. It could be the point at which the aroma is most impressive, the point where the body is best developed or the coffee the sweetest or contrarily the least bitter. This requires roasting a spread of various degrees of roast and performing comparative cupping to determine which is more suitable or flexible for your needs.
Sometimes we roast with different profiles. Slow and fast roasting produces different results. Ordinarily slow roasting is more suitable for espresso in as much as it mutes acidity. Fast roasting on the other hand accentuates acidity, which is particularly good for drip and urn coffees.
Sometimes you may want to make a sample blend at the cupping table. For drip or urn coffees you can actually blend from the cup samples for quick reference. One spoonful of this and one spoonful of that. If you like the result you can blend the beans of the two samples and re-cup. It’s not definitive but it’s a start.
One reason cuppers like to make their first assessment at a standard lighter roast is because any defect in taste will be more noticeable. A second roast of all acceptable samples passing the first taste test is then assessed at the desired roast to ascertain which sample meets expectations.
When comparing tastes of coffees from the same origin, it is advantageous to have all samples roasted to the same degree so one is not tasting the difference in roasts but the actual flavor.
Timed roasting on simple home roasters is not appropriate as roasting times differ considerably determined by the coffee density, moisture content and sometimes processing method, not to mention decaf. Changes in line voltage will also affect home roasters performance.
Sample roasting is generally done by eye and sometimes by sound if the popping sound of the beans is audible. Many stop their roast at the first crack.
With experience, one can come very close each time but mistakes still happen and it is good to have enough sample to make a second roast.
Sometimes we will roast light to see if the coffee is suitable for a particular blend and roast darker to see if it will work in the espresso blend. French Roast samples have to be roasted dark to determine suitability.