Condensed milk is obtained by the partial removal of water from whole or skim milk that has been pasteurized and to which nothing has been added. The product is canned or packaged in other containers without sterilization in a procedure known as osmoanabiosis—the prevention of microbial growth by increasing osmotic pressure on the medium. The minimum sugar content is often not precisely specified, but should be sufficient to avoid spoilage. Frequently, this product is fortified with the addition of vitamins—mainly A, D3 and B1.