Expressed as a ratio of water to grain—a typical amount would be 2.6L/kg (1.25qt/1 lbs), that is, 2.6 L of water per kilogram of grain. However, this number can vary in a wide range from 1.7L/kg (0.8qt/lbs) up to 5.1L/kg (2.5qt/lbs) depending on the style and type of mash (more on mash types to follow). If the mash is too thick then the enzymes can’t get out to the starches to convert them. If the mash was too thin then there is too much liquid between the enzymes and the starch molecules and they just never meet.