Starch Attack
Enzymes break down rye starch in the oven, leaving a gummy crumb.
A rye bread fault where amylase enzymes break down starch during baking, leaving a sticky, gummy, or cracked crumb that can pull away from the crust. Rye starch gelatinizes at temperatures where these enzymes are still active, so the enzymes get a window to break it down before the bake sets the crumb. Acidity from a rye sourdough slows that enzyme activity, which is a big reason traditional rye breads are made with sourdough.
By Henry Hunter · Updated
Diagnose and fix
Rye loaf is gummy or sticky inside even after cooling
Use enough sourdough to acidify the dough well, and let the loaf rest before slicing. Many rye breads need a full day to set.
Crumb cracks or separates from the crust
Check your acidity and baking. More ripe rye sourdough and a full bake usually help. Flour with high enzyme activity, such as sprout-damaged flour, makes this more likely.
Problem appeared with a new bag of rye flour
Enzyme levels vary between harvests and mills. Try a higher share of rye sourdough in the dough, or a different flour.