Does water hardness affect yeast-leavened doughs?
Water hardness refers to the calcium and magnesium ions in the water. Levels will vary by locality, and sources such as wells, rivers, or reservoirs. Your local water company should be able to supply you with this information. Yes, hardness will affect yeast-leavened dough. Medium soft water (50 to 100 ppm) is considered to be the desired level of hardness. Soft water (0 to 15 ppm) is undesirable because it tends to soften the gluten and produce slack, sticky doughs and a finished product with a more open grain. The use of mineral yeast food or a slight increase in salt level would supply the hardness necessary to improve the absorption and crumb structure. Some hard waters (200 ppm and higher) are objectionable because they can elevate the pH of the dough, causing a retarding effect on yeast and enzyme activity. This prolongs fermentation and affects machinability of the dough. Additions of lactic acid, acetic acid and monocalcium phosphate are easy corrections for this problem.