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.
Trickling Springs Organic and Trickling Springs FarmFriend CreamLine milk is milk that has not been homogenized. Milk fresh from the cow will naturally separate with the cream rising to the top. Homogenization is the process of breaking those fat molecules into very small pieces so they will not separate.