Fermentation stability of frozen prefermented doughs was studied with a maturograph, an instrument that allows monitoring of dough rise, gas production, and gas retention during fermentation. Maturograph curves excellently predicted the baking quality, measured as form ratio, after frozen storage. The greatest decrease in dough level occurred after seven days of storage, after which the level remained constant. With some flours, decreased amount of water improved both the fermentation stability and form ratio of breads baked after seven days of frozen storage of dough. However, no improvement was observed in loaf volume. Preliminary experiments with longer final fermentation time (after thawing) showed that the reduced water content also resulted in higher loaf volumes than did optimal water content. Microscopic studies showed that with most doughs, porosity decreased with reduced water content. However, these changes depended on flour type. In one dough, reduction of water by 2 percentage units decreased the area of pores per total area of section from 56.6 to 46.4%, whereas in another dough the same water reduction had no effect on the pore area.