It is found in the juice of grapes[1][2] (Vitis vinifera) and impacts the color of white wine.

Caffeic acid is susceptible to chemical oxidation, and subsequent redox reactions involving caffeic acid can contribute to wine browning over time, and the straw-gold color that can develop in some white wines after bottling.

It also occurs in Cichorium intybus (common chicory) and is one of the bioactive components of Echinacea purpurea (Eastern purple coneflower).

For example, press wines, which undergo a high degree of oxidation[citation needed], will have little to no caftaric acid.

Malvidin 3-glucoside alone is not oxidized in the presence of grape polyphenol oxidase (PPO), whereas it is degraded in the presence of a crude grape PPO extract and of caftaric acid, forming anthocyanidin-caftaric acid adducts.