Integrated impact of wheat classes, particle size, and fermentation time on the quality of whole wheat sourdough bread from stone milled flour

Sourdough (SD) bread quality is shaped by fermentation driven biochemical changes influenced by wheat class, fermentation time, and flour particle size (PS ) , yet their combined effects, particularly in stone milled flours remain inadequately understood. This study evaluated these factors using whole wheat flour (WWF) from hard red spring (HRS ) compared to the hard red winter (HRW) and hard white wheat (HWW), and their 50:50 blends with HRS. Grains were stone milled at wide, medium, and narrow gaps, and analyzed for physicochemical, functional, and rheological properties. SD breads were prepared using two fermentation times (12 h and 24 h ) and analyzed for physical, functional and sensory qualities. HRS exhibited the strongest dough characteristics. Accordingly, a 50% HRS blend with HRW or HWW increased their stability from 5.64 to 8.05 min, and from 5.48 to 8.60 min, respectively . Blending also balanced viscoelasticity of the dough. On the other hand, PS reduction improved SD bread quality by increasing volume by 13.48% and reducing hardness by 23.23%. Extending fermentation to 24 h reduced volume by 4.12% and increased hardness by 10.98%, while enhancing aroma via increased organic acids. Overall, breads prepared from HWW and HRS: HWW blend using fine PS flour and a 12 h fermentation exhibited the best overall quality. Notably, the HRS: HWW blend uniquely maintained comparable quality after 24 h fermentation, indicating greater tolerance to prolonged SD fermentation. These findings provide practical guidance for optimizing SD bread formulations based on wheat class selection, milling, and fermentation control.