AlegsaOnline.com Home Food Postum Postum Author: Leandro Alegsa Creation date: November 13, 2022 en.wikipedia.org · No restrictions Postum is a drink first made by C. W. Post in 1895. It is a powder substitute for coffee that is mixed with water. The ingredients are wheat bran, wheat, molasses, and corn dextrin. It is advertised as a healthier choice of drink than coffee.