What is Brix in coffee?

Brix is a measurement of the sugar content of a liquid, expressed as grams of sucrose per 100 grams of solution. In coffee, it's used primarily at the farm level to measure the sugar concentration of ripe coffee cherry - providing an objective indicator of cherry ripeness and quality potential at harvest.

A refractometer - a small handheld optical device - is used to measure Brix in the field. A drop of juice squeezed from a coffee cherry is placed on the lens; the device reads the sugar concentration by measuring how the liquid bends light. Ripe specialty-grade cherry typically reads between 18-24 degrees Brix, though this varies by variety and growing conditions. Lower Brix suggests underripe cherry; higher readings indicate peak or slightly past-peak ripeness.

For specialty producers and buyers who pay attention to harvest precision, Brix measurements are a useful tool for deciding when to pick and for setting intake standards at the wet mill. Cherry accepted at the washing station can be tested on arrival, with lots below a minimum Brix threshold rejected or separated. It brings objectivity to a decision - cherry ripeness - that is otherwise left to the pickers' judgement.