Postum was a grain-based beverage made by Kraft. It has now been discontinued. This is supposed to be a good substitute. Use more or less per cup depending on how strong you like it. This recipe is from Cooks.com and I have not tried it.
Serving Size: 1 (22) g
Servings Per Recipe: 48
Calories: 76.2
Calories from Fat 4 g 6 %
Total Fat 0.5 g 0 %
Saturated Fat 0.1 g 0 %
Cholesterol 0 mg 0 %
Sodium 3.4 mg 0 %
Total Carbohydrate 17.1 g 5 %
Dietary Fiber 2.1 g 8 %
Sugars 2 g 8 %
Protein 1.9 g 3 %