🧀 Milk powder

Milk powder is made by removing water from milk. Under Codex standard CXS 207 and EU Directive 2001/114 it contains no more than 5% water ³⁴. The standard distinguishes cream powder (from 42% fat), whole milk powder (26–42%), partly skimmed (1.5–26%) and skimmed (up to 1.5%), and milk solids-not-fat must contain at least 34% protein ³.

Drying straight away is uneconomical. Milk is first concentrated under vacuum at 55–70 °C to 48–50% solids, because this takes only 10–12% of the energy of spray drying ⁸. It is then sprayed into an air stream at 150–300 °C. The water evaporates so fast that the droplet cools to about 50 °C ⁸. Roller drying is not often used for milk products ⁸.

Powders differ in heat treatment, from mild, 70 °C for 15 seconds, to strong, about 125 °C for 3 minutes. The heat load determines how much whey protein is denatured and which product the powder suits ⁹. To make powder dissolve faster, its particles are agglomerated, and some types are sprayed with lecithin ⁸⁹.

According to USDA, 100 g of whole milk powder has 496 kcal, 26.3 g of protein and 912 mg of calcium, and skimmed powder 362 kcal, 36.2 g of protein and 1260 mg of calcium ¹². Drying costs vitamins: in a study cited by FAO, spray drying removed 93% of vitamin C, 60% of vitamin A, 40% of tocopherols and 30% of riboflavin ⁵.

Skimmed powder keeps about three years in cool, dry conditions, and whole powder far less, because the fat turns rancid ⁵. So less than 7% of world milk is traded internationally, but about half of whole and skimmed powder ⁶. New Zealand remains the main supplier of whole milk powder, and powder goes mostly into confectionery, infant formula and bakery products ⁶.

Milk powder or fresh milk? Powder is milk with the water taken out, no more than 5% left, so it is made from the same milk, cream or skimmed milk. The difference lies in the process: vacuum concentration, then spraying into hot air, which costs some vitamins. Whole powder has 496 kcal and 26.3 g of protein per 100 g, skimmed powder 362 kcal and 36.2 g, because its fat is gone. Powder is also not infant formula, even though both are dried.

Packs say "whole milk powder", "skimmed milk powder" or "milk powder", and under EU rules must show the fat content and how to reconstitute it. Look for the statement that it is not intended for infants under 12 months. It sits in the baking or dairy aisle of a supermarket, or at a wholesale or ethnic grocer, in tubs, bags or sachets. Choose by the fat level you want: skimmed has up to 1.5%.

Why it matters to you. In the EU, the pack must show the fat content and how to reconstitute the powder, so follow it ⁴. In industry, milk is reconstituted at 40–50 °C and left for about 20 minutes, otherwise a chalky taste or sediment remains ⁹. Keep the pack tightly closed in a cool, dry place. Milk powder is not infant formula: the EU directive requires a statement that it is not intended for infants under 12 months, and the NHS advises against giving it to babies under one ⁴⁷.