Also known as caproic or capronic acid, this six-carbon member of the fatty-acid family belongs to the aliphatic carboxylic acids. It enriches the taste and smell of many foods — cheese included — where its piquant, goaty character marks ripened varieties. At low levels it enriches flavour complexity; at high levels it turns sharp and rancid, so dairy scientists monitor it as a ripening indicator and as a marker of lipolysis in milk products. Beyond dairy, it appears in fermented foods and beverages wherever short-chain fatty acids shape character, and its balance is one of the fine details cheesemakers manage during maturation.