What is malic acid in coffee?

Malic acid is one of the key organic acids in Arabica coffee, contributing to the apple-like, stone fruit, and soft berry acidity associated with certain origins and varietals. It's naturally present in the coffee cherry and is one of the acids that persists through processing into the green bean.

Malic acid is the dominant acid in apples and many stone fruits, which is why coffees high in malic acid are often described with those fruit references during cupping. It's generally perceived as softer and rounder than citric acid - where citric acid produces bright, citrus-like brightness, malic acid tends to read as fruit sweetness with a gentler acid structure.

Origins and varietals influence malic acid expression. Ethiopian and Kenyan coffees often show pronounced malic alongside citric character. Processing method also plays a role - natural-processed coffees, where the bean spends more time in contact with the drying fruit, can show elevated malic acid expression compared to washed lots from the same cherry. Malic acid is degraded during roasting, which is why it's most expressive in lighter roast profiles.