Definition of substitution. 1  1a : the act, process, or result of substituting one thing for anotherb : replacement of one mathematical entity by another of equal value. 2  2 : one that is substituted for another.
Homogenized milk is any sort of milk that has been mechanically treated to ensure that it has a smooth, even consistency. The homogenization process typically involves high temperatures, agitation, and filtration, all aimed at breaking down milk's naturally occurring fat molecules.
Learn more about what evaporated milk is, and what to substitute for it when cooking. Evaporated milk is milk that has been cooked down to allow some of the water content to evaporate. The concentrate is canned, and the result is a heavier tasting milk with a slightly toasted or caramelized flavor.