From the 16th century through the 19th century, whale oil was used principally as lamp fuel and for producing soap. Long utilized for lubricating fine instruments, whale oil was treated with sulfur to provide high-pressure lubricants used in machinery, and it was also important in the manufacture of varnish, leather, linoleum, and rough cloth (especially jute).
In the first half of the 20th century, whale oil’s applications broadened immensely. Premodern oil was inedible, but advances in chemistry allowed fresh oil to be hardened into a fat, which was used for margarine and soap until vegetable oil became a practical alternative in the late 1930s. Whale oil was extremely important in the manufacture of nitroglycerin for explosives in both world wars, and whale liver oil was a major source of vitamin D through the 1960s.
Production of whale oil during the 20th century usually took place on large factory ships, where minced whale blubber, bones, and flesh were cooked under steam pressure. Blubber yielded 50–80 percent oil by weight, bones 10–70 percent, and meat 2–8 percent. Fatty acids for soaps and fatty alcohols for cosmetics and detergents were derived by immersing whale oil fats in alkalis. Textile sizings were made from hardened oil.