Does lactose-free milk work in coffee?

Yes, and it behaves better than most people expect.

How it is made

Lactose-free dairy milk is ordinary milk with the enzyme lactase added, which splits lactose into glucose and galactose. Nothing is removed.

That matters for coffee: the proteins and fats that build and stabilise foam are untouched, so it steams and foams essentially like normal milk.

The taste

Noticeably sweeter. Glucose and galactose taste sweeter to us than lactose does, even though the total sugar is identical.

Some people love this in coffee and some find it cloying. It is the main reason to try before committing.

Steaming it

Same technique, same temperatures. If anything it is slightly more forgiving, and the extra perceived sweetness survives being slightly overheated better than normal milk.

Versus plant milks

If your reason for avoiding dairy is lactose rather than dairy itself, lactose-free milk is a considerably better coffee ingredient than any plant alternative — it foams like milk because it is milk.

Availability

Widely stocked in most of Europe, including in whole-fat versions, which are the ones you want. Skimmed lactose-free foams stiffly for the same reason skimmed dairy does.