A short review is given of the methods used until 1986. Discusses why, among all organic materials, fat is the most useful for trace analysis. Diagrams show the decomposition, by heat, of starch, sugar, casein, cholesterol, and wheat and the changes that fat (of barley) undergoes. Further, the autooxidation of linolic and linolenic acid methyl ester at room temperature and open air is shown. Examples are discussed for identification of fats, with special respect to vessels for wine and beer.