fresh milk

Fresh milk (Bos taurus, the milk itself) turns up in seven recipes here, in amounts from a 20 ml splash to 250 ml. The egg-free brownies use the splash only if the batter is too thick, and the recipe allows water instead. The oat waffles whisk 160 ml in with the egg, the strawberry banana smoothie takes 240 ml, dairy or plant-based, and the green protein smoothie 250 ml of full-fat milk. In the three rose milk teas it goes in last, 80 ml after the tea is strained.

The Journal's note on astringency explains why that order matters. Astringency, the rough, puckering feel of an over-steeped black tea, is not a taste: it travels on the trigeminal nerve, and polyphenols bind the proline-rich proteins that make up about seventy per cent of saliva's protein. Milk cuts it, as tea drinkers have long known, and the usual reason given is that milk proteins bind the tannins first. A 2009 study found milk reduced astringency while making oral lubrication considerably worse, so the note's verdict is a reliable technique with a shaky explanation.

Milk is also an odd drink for an adult. Nearly every mammal switches off its lactose-digesting enzyme after weaning, and the note on yogurt and lactase persistence traces how some humans did not: a single-letter variant in Europe, at least three different ones in East Africa. Milk use in Europe began close to the start of farming, yet persistence only became common around 1000 BC. The bloating note adds a working number: Monash puts 250 ml of full-cream milk at 15.75 g of lactose, while most lactose-intolerant adults tolerate about 12 g in one sitting, roughly a cup.