Fat in dry matter
The fat in a cheese expressed as a share of its solids, the figure printed on most European labels.
Also: FDM, FiDM, matière grasse sur extrait sec, Fett i. Tr.
Fat in dry matter is how cheese fat is usually measured and labelled in Europe. Instead of giving fat as a percentage of the whole cheese, which shifts as water evaporates, it gives fat as a percentage of everything that is not water. A Brie labelled forty-five per cent fat in dry matter, for instance, may contain only about twenty-five per cent fat by total weight, because half the cheese is water. The figure stays constant from young to old, so it is useful for defining types, such as double-cream at sixty per cent and triple-cream at seventy-five. German labels write it as Fett i. Tr. and French as MG/ES.