Soap and cosmetic products can be made from oil-bearing microbial biomass via the alkaline hydrolysis of glycerolipids and fatty acid esters to fatty acid salts. The saponified microbial oils/lipids can be combined with a variety of additives to produce compositions for use as soaps and other cosmetic products, which may also contain other constituents of the biomass, including unsaponified oils, glycerol and carotenoids, among others.