When roasting, sound is an excellent indicator. Roasters listen for two temperature thresholds known as “cracks.” We’ll let you know about the first and second cracks.
One of the most crucial factors in roasting is the roast temperature and roast duration. There is a danger that the beans can burn if your roaster has an excessively high temperature. You won’t obtain the desired outcome if it is too low either. There are two temperature thresholds known as “cracks” that roasters watch for when discussing time.
The meaning of first crack
Approximately 196 °C (385 °F) will cause the coffee to start cracking. The start of a lighter roast is what we call the “first crack” at this point. The first crack occurs when a significant portion of the moisture in the coffee has evaporated, causing the beans to enlarge. When you are reproducing a specific profile, the first crack is an excellent indicator.
A second one, logically referred to as the “second crack,” will come after the first one and a little more roasting time. The roaster’s inside is currently 224 °C hot. After a light, average, or dark roast is finished, this second noise will be heard. The majority of roasters favor these beans, but you have the option to keep roasting and wait for the second batch to yield an Italian or French roast. The bean’s structure is now starting to disintegrate. The oils that will surface lead them to darken and appear shinier.