Pentosans

Pentosans, also called arabinoxylans, are fiber-like carbohydrates found in the cell walls of grains. They can hold many times their own weight in water, forming a sticky, gel-like mass. In rye they do much of the work gluten does in wheat, giving rye dough its paste-like feel and helping hold the loaf together. Wheat has them too, more so in whole grain flour, and they're part of why whole wheat and rye doughs need more water.

By Henry Hunter · Updated October 1, 2026

Henry's notes from the bench

• Rye dough feels like clay, not like wheat dough, and that's the pentosans at work. Don't try to knead it into a smooth ball. Mix it well, wet your hands, and shape it gently.