It is a complicated set of principles when it comes to moisture.
Too much is indeed bad at the beginning of the roasting process. Driving off too much moisture in the initial phase of roasting could lead to an extended drying phase and longer roasts, potentially baking the coffee. This tends to leave the coffee tasting flat and hollow.
12% moisture however , is deemed acceptable for a couple of reasons.
1, likelihood of bacteria and fungus production is significantly reduced if stored and handled correctly.
2, there is enough moisture present to allow adequate heat transfer in the initial stages of the roast, this will dictate the rate at which specific chemical reactions take place that build flavour and aroma in the later stages.
Too little moisture will speed up the rate of heat transfer, and can lead to quick roasts that tend to cause underdevelopment. Cooked on the outside but raw on the inside.
It is a constant battle to manage.
Water is good - water is bad - water is life...
Thanks for reading and taking the time to comment. It is much appreciated.
I’m surprised that greater moisture content at the beginning of the roasting process results in a better cup. Would’ve assumed the opposite was true.
Hi Matthew,
It is a complicated set of principles when it comes to moisture.
Too much is indeed bad at the beginning of the roasting process. Driving off too much moisture in the initial phase of roasting could lead to an extended drying phase and longer roasts, potentially baking the coffee. This tends to leave the coffee tasting flat and hollow.
12% moisture however , is deemed acceptable for a couple of reasons.
1, likelihood of bacteria and fungus production is significantly reduced if stored and handled correctly.
2, there is enough moisture present to allow adequate heat transfer in the initial stages of the roast, this will dictate the rate at which specific chemical reactions take place that build flavour and aroma in the later stages.
Too little moisture will speed up the rate of heat transfer, and can lead to quick roasts that tend to cause underdevelopment. Cooked on the outside but raw on the inside.
It is a constant battle to manage.
Water is good - water is bad - water is life...
Thanks for reading and taking the time to comment. It is much appreciated.