The essential ingredients are flour, water, and yeast. The liquid may be milk, or milk and water, the milk changing the flavor slightly and increasing the nutritive value, while the cream in the milk increases the tenderness of the crumb and crust. The non-essentials include salt to develop flavor, sugar sometimes added to hasten fermentation and also for flavor, and a fat to increase tenderness, as, for instance, butter or some cheaper fat. Spices and dried fruits are used in sweet breads, and when eggs are added sweet bread becomes a plain cake having a delicious and characteristic flavor.