Diastase
Lexikon
Diastase is an enzyme that bees add to honey during processing and that can break down starch-like carbohydrates.
Diastase is an enzyme that bees add to honey during processing and that can break down starch-like carbohydrates. It matters for honey testing mainly because it is damaged by heat and long storage, so a low value can point to excessive heating or unsuitable storage. The so-called Schade diastase number indicates how active this enzyme still is in the honey.
The Honey Regulation (Germany) legally requires a diastase number of at least 8; for honey varieties with a naturally low enzyme content, at least 3 is sufficient. The German Beekeepers' Association (Deutscher Imkerbund) deliberately does without its own, stricter diastase value in its trademark statutes, because measuring invertase activity and HMF content shows the effects of heat and storage more sensitively than the diastase number does. The German Honey Guidelines (Leitsätze) also set no value of their own, so for diastase the requirement of the Honey Regulation ultimately always applies.
In practice, diastase is measured in isolation less often than HMF or invertase, because it reacts less sensitively and is therefore less informative for assessing gentle processing. A common misunderstanding is equating the diastase number with the ripeness of a honey; in fact it mainly says something about heat exposure after harvest, and in some varieties such as rapeseed honey or acacia honey it is naturally low anyway, without this being a quality defect.