What does… actually mean?
“FDM” written out means: fat in dry matter. This is the fat mass percentage of the cheese dry matter, i.e. all the cheese’s components (except water). FDM therefore only refers to the fat content in the dry matter. At the same time it is unimportant how much water the cheese contains. According to the cheese regulation, the fat content in dry matter or the fat content must be specified with cheese. Normally you can recognise fatty cheese as having a FDM over 40%.
The cheese’s fat formula
Cheese is made up of dry matter and water. During maturing and storage, the water evaporates and therefore the cheese loses weight. The actual fat content is therefore lower than the reported value. There are formulas with which you can work out the absolute fat content. For hard cheese for example, multiply the FDM by 0.7, for mozzarella multiply the FDM by 0.4 and for semi-hard cheese multiply the FDM by 0.6. Cream cheese and quark are usually lighter than you believe as a result of the specified “FDM” value.