The 20th century brought two broad trends to Europe and North America. One was a decline in the per capita consumption of plain bread. As incomes rose, people could afford to eat more meat and more high-sugar, high-fat cakes and pastries. So we now lean less heavily than did our ancestors on the staff of life. The other trend was the industrialization of bread making. Today very little bread is made in the home, and with the exception of countries with a strong tradition of buying fresh bread every day—especially France, Germany, and Italy—most bread is made in large central factories, not in small local bakeries. Mechanical aids to breadmaking, powered mixers and others, began to appear around 1900, and culminated in the 1960s in largely automated factories that produce bread in a fraction of the usual time. These manufacturing systems replace biological dough development, the gradual, hours-long leavening and gluten strengthening of the dough by yeast, with nearly instantaneous, mechanical and chemical dough development. This production method produces breads with a soft, cake-like interior, an uncrusty crust, and an uncharacteristic flavor. They are formulated to remain soft and edible in plastic bags for a week or more. Industrial breads bear little resemblance to traditional breads.