The milk argument, settled

There are two kinds of people: those who add the milk at the start, and those who are wrong. It is an argument worth having properly once and then never again, so here it is.

What boiling actually does

When milk goes into the pan with the tea and comes up to the boil, three things happen. The fat carries the spice — cardamom and clove are oil-soluble, and water alone will not pull them properly. The proteins denature and thicken the whole thing very slightly, which is where the body comes from. And the milk sugars start to brown, which is the caramel note you cannot get any other way.

Pour cold milk into finished black tea and you get none of that. You get black tea, cooled down, with milk in it. It is a perfectly nice drink. It is not chai.

Chai is not steeped. It is cooked.

The three-climbs rule

Once the milk is in, the pan will foam up and climb the sides. Let it. Pull it off the heat as it reaches the rim, let it drop, put it back. Do this three times. The first climb is thin, the second is thicker, and by the third the colour has gone from grey-beige to the colour of wet sand. That colour is the whole test. If you are looking at something pale, it needs another minute.

Why three and not four? Four is fine. Six and it starts to taste stewed and slightly tinny. Somewhere around three is where it stops improving, and stopping when a thing stops improving is most of cooking.

The one exception

If you are using oat milk, put it in at the end and keep it under a hard boil, because most oat milks split when they are cooked that long and you will be picking bits out of the strainer. A barista formulation behaves better than a standard one — they are stabilised for exactly this.

That is the argument. Milk at the start. Unless it is oat, in which case, fine, it is allowed, but nobody is happy about it.