🔄 Milking

Milking is drawing milk from the udder of a cow, goat, sheep, buffalo or other animal, by hand or with a milking machine. Milk flows thanks to the let-down reflex: when the teats are prepared for milking, the pituitary gland releases the hormone oxytocin, and within about a minute the milk reaches the teats. Pain or fear inhibit this reflex, so a calm animal matters.

Before milking, the teats and udder have to be clean: dirt is washed off and the udder is wiped dry. The first squirts of milk are drawn off separately, which makes it easy to spot mastitis, an inflammation of the udder. Milk from sick animals is not poured into the common container. Even after good milking, at least 10% of the milk stays in the udder.

Cows are usually milked twice a day; equal intervals of 12 hours give the highest yield. Milking three times a day adds 10–15% more milk on average, but part of the gain goes on extra costs. After the teat cups are attached, milk flow peaks within about a minute at 2–5 kg per minute, and milking itself takes 2–8 minutes depending on the yield. A modern machine removes about 95% of the available milk.

Hand milking or machine milking? Both rely on the let-down reflex, and both need clean teats and a calm animal; a modern machine removes about 95% of the available milk, with flow peaking at 2–5 kg per minute. Twice or three times a day? Twice at equal 12-hour intervals gives the highest yield per milking, while a third milking adds 10–15% more milk on average, though part of the gain goes on extra costs. Whatever the method, at least 10% of the milk stays in the udder, so no one can milk out everything.

Milking never appears on the pack, but its result does: look for the milk type, such as “raw milk” for milk that has not been heat-treated, and for the date and storage temperature. Packs sit in the chilled counter of supermarkets and dairies, and raw milk is sold mainly through farm outlets. Milk’s natural protective substances hold bacteria back for only 3–4 hours, which is why cooling matters: in the EU, to no more than 8 °C if it is collected daily.

Why it matters to you. The quality of the milk in your glass depends on milking. In a healthy udder, milk is almost sterile; bacteria get into it during and after milking. Milk's natural protective substances hold them back for only 3–4 hours, so milk has to be cooled quickly: in the EU, to no more than 8 °C if it is collected daily and no more than 6 °C if less often.