A term used by millers and bakers to refer to the alpha-amylase activity in flour. The falling number (FN) value has an inverse relationship with the alpha-amylase activity meaning the higher the alpha-amylase activity the lower the FN value, and vice-versa. For many flours, the falling number is adjusted through the addition of diastatic malt, or fungal amylase, to increase the level of enzymatic activity for optimum dough performance. Such adjustments are usually done at the mill, but sometimes by the baker.

Malted bread flours typically have falling numbers of 250–290. Generally, a falling number value of 350 or greater indicates low enzyme activity. Values below 200 indicate high levels of enzyme activity. For comparison purposes, the King Arthur Sir Lancelot flour, which is a malted flour, has a falling number of 250 ± 30 seconds. By contrast, the Caputo 00 pizzeria flour, which is unmalted, has a falling number of 340–360 seconds. Quite often, the falling number alone will indicate whether a particular flour is malted or not. See also ALPHA-AMYLASE.