by kneading, or wet dough is allowed to rise for a long time (see no-knead bread), the glutenin forms strands of long, thin, chainlike molecules, while the shorter gliadin forms bridges between the strands of glutenin. The resulting networks of strands produced by these two proteins are known as gluten. Gluten development improves if the dough is allowed to autolyse. Liquids Water, or some other liquid, is used to form the flour into a paste or dough. The weight or ratio of liquid required varies between recipes, but a ratio of three parts liquid to five parts flour is common for yeast breads. Recipes that use steam as the primary leavening method may have a liquid content in excess of one part liquid to one part flour. Instead of water, recipes may use liquids such as milk or other dairy products (including buttermilk or yogurt), fruit juice, or eggs. These contribute additional sweeteners, fats, or leavening components, as well as water. Fats or shortenings Fats, such as butter, vegetable oils, lard, or that contained in eggs, affect the development of gluten in breads by coating and lubricating the individual strands of protein. They also help to hold the structure together. If too much fat is included in a bread dough, the lubrication effect causes the protein structures to divide. A fat content of approximately 3% by weight is the concentration that produces the greatest leavening action. In addition to their effects on leavening, fats also serve to tenderize breads and preserve freshness. Bread improvers Bread improvers and dough conditioners are often used in producing commercial breads to reduce the time needed for rising and to improve texture and volume and to give antistaling effects. The substances used may be oxidising agents to strengthen the dough or reducing agents to develop gluten and reduce mixing time, emulsifiers to strengthen the dough or to provide other properties such as making slicing easier, or enzymes to increase gas production. Salt Salt (sodium chloride) is very often added to enhance flavor and restrict yeast activity. It also affects the crumb and the overall texture by stabilizing and strengthening the gluten. Some artisan bakers forego early addition of salt to the dough, whether wholemeal or refined, and wait until after a 20-minute rest to allow the dough to autolyse. Mixtures of salts are sometimes employed, such as employing potassium chloride to reduce the sodium level,