☕ Milk in the kitchen: dishes and drinks

Milk in the kitchen: dishes and drinks covers how milk behaves in the saucepan, in dough and in the cup: from porridge, blini and béchamel to coffee, cocoa and tea with milk.

When milk is heated, the whey proteins change first: they start to denature at 65 °C and are almost fully denatured after 5 minutes at 90 °C. Above 100 °C lactose reacts with the proteins in the Maillard reaction: the milk turns brown, takes on a caramel flavour and loses part of the amino acid lysine. That is why long boiling and baking noticeably change its colour and taste.

Acid «curdles» milk because casein, the main milk protein, precipitates at a pH of about 4.6. Fermented milk products and cheese rely on this: according to FAO, cheese is made by coagulating the casein and separating the whey.

Fresh milk separates over time: the fat globules are lighter than the rest of the milk and slowly rise to form a layer of cream. Homogenization slows this down, which is why cream does not usually gather on packaged milk.

Boiling also has a practical purpose. Raw milk may carry pathogens, and EFSA notes that people buying milk from vending machines are usually advised to boil it, which removes the microbiological risks. For children over 12 months the NHS allows 1% and skimmed milk to be used in cooking. At breakfast milk goes with cereal and porridge, in the kitchen into pastry dough and syrniki, and in the café into cappuccino and latte.