Over extraction happens when too much flavor is pulled from the coffee grounds, resulting in a harsh and unpleasant taste. This is a common problem in coffee brewing, especially for those who are still learning how to make their own coffee at home. Understanding what over extraction is and how to prevent it can help you brew a delicious cup of joe every time.
Causes of Over Extraction
When hot water runs through ground coffee beans, the parts of the bean that can dissolve into the water do just that. Just under 30% of the average coffee bean is water-soluble. However, not all of that thirty percent tastes good, so we aim for a little lower than that.
There are a few ways to over-extract your coffee, depending on the brewing process. The three factors are water temperature, grind size and brew time. Any of these can play a role in over-extracted coffee by increasing the amount of bad-tasting components in your final result.
Tastes and Prevention
Over extracted coffees taste bitter, acidic and heavy. The burnt flavor comes from over-roasting. The bitterness is from high caffeine and acid content being drawn out.
To prevent over-extraction, use the right ratios for your brew method. With pour over, don’t let water drain through grounds after it appears fully drained. Try adjusting grind size coarser or reducing contact time between grounds and water. Diluting an over-extracted brew with more water can also help balance the flavor. Experimenting with these factors creates unique flavors but avoiding charred, bitter tastes signs optimal extraction.