Coffee Concentration

What coffee concentration means

Coffee concentration describes the proportion of dissolved coffee compounds in a brewed beverage. It influences perceived strength, but it is not the same as extraction. Concentration concerns how strong the beverage is, while extraction concerns how much soluble material was removed from the grounds.

Concentration and extraction

A concentrated cup can still be under-extracted, and a dilute cup can be well extracted. Flavor therefore depends on both variables:

• Concentration: the amount of dissolved coffee material relative to the finished beverage.
• Extraction: the proportion of soluble material transferred from the dry coffee into the water.
• Brew ratio: the relationship between dry coffee and brewing water.

Under-extraction often produces sharp, sour, or thin flavors. Excessive extraction may produce bitterness, dryness, or astringency. These sensory results can also be affected by roast, water, temperature, grind uniformity, and brewing technique.

How concentration is measured

A coffee refractometer can estimate total dissolved solids, commonly abbreviated as TDS. TDS is expressed as a percentage of the beverage. The reading can be combined with beverage mass and dry coffee dose to estimate extraction yield.

For a dependable comparison, allow the sample to cool as directed by the instrument, filter it when necessary, calibrate the refractometer, and take repeated readings.

Adjusting a brew

• Use more coffee or less water to increase concentration.
• Use less coffee or more water to decrease concentration.
• Grind finer, extend contact time, or increase agitation when greater extraction is needed.
• Grind coarser, shorten contact time, or reduce agitation when extraction is excessive.

Change one variable at a time and record the dose, water mass, grind setting, brew time, beverage yield, and sensory result. Measurements are most useful when they support tasting rather than replace it.