A process and a plant are specified, with which free fatty acids can be obtained in a simple manner by hydrolysis of fatty acid alkyl esters, especially fatty acid methyl esters (FAME), or alternatively of fatty acid triglycerides present in oils and fats of vegetable and animal origin. According to the invention, a portion of the free fatty acids already produced is recycled back into the reaction mixture, which results in self-acceleration of the hydrolysis reaction.