After churning, the mass of butter is washed and salted. It is worked to distribute the salt and remove extra water. To be sold in stores, butter must contain at least 80 percent milk fat. Water and milk solids make up the other 20 percent. Salt and coloring may be added if desired.
Some unsalted butter is sold as sweet butter, but most people prefer the salted product.
Commodity butter is distributed as blocks. The USDA grade label on the butter carton or wrapper means the butter has been tested for quality by a government grader and has been produced under sanitary conditions. Grade AA butter is delicate and sweet-flavored with a creamy texture and good spreadability. Most butter sold is grade AA or A. Butter in the diet Because of its high fat content, butter belongs to the food group called Fats, Sweets and Alcohol. Foods in this group contain many calories but few nutrients such as protein, vitamins and minerals.