Falling Number

Falling number is a lab test for alpha-amylase activity, the enzyme that breaks starch into sugars. A flour and water slurry is heated, and the test measures how many seconds a stirrer takes to fall through it. A low number means lots of enzyme activity, often from sprout damage, and that flour can give a sticky, gummy crumb. A high number means little activity, which can mean slow fermentation and a pale crust, and mills often correct it by adding malted barley flour. Mills usually aim for a middle range for bread flour.

By Henry Hunter · Updated October 1, 2026

Henry's notes from the bench

• Home millers can't run a falling number test, but your bread will hint at it. If a new batch of berries suddenly gives you a sticky crumb with no other changes, enzyme activity is a good suspect.