Butter is a concentrated form of milkfat made exclusively from milk or cream, or both, with or without common salt, and with or without additional coloring matter, and containing not less than 80% by weight of milkfat, all tolerances having been allowed for storage refrigerate at 32-38¦f for up to four months. Relative humidity should be kept between 80 and 85 percent. Freeze at negative 10¦f to negative 20¦f for up to one year. Relative humidity should be kept between 80 and 85 percent. Butter should be kept sealed, in a dry poly-lined carton.