You order the same flat white every day. Same beans, same size — but change the milk and you quietly change the sugar. Some of it's natural, some isn't, and the difference between oat, almond, soya and semi-skimmed is bigger than most people think. Let's open the fridge.
Semi-skimmed milk has no added sugar, but it isn't sugar-free either. It naturally contains lactose — around 4.7 grams per 100 millilitres. In a typical flat white's worth, that's close to two teaspoons, before your coffee's even been sweetened. It's just... what milk is.
Oat milk gets its sweetness from processing — enzymes break starch down into sugars so it froths and tastes right. A typical barista oat milk runs around 6.5 grams of sugar per 100 millilitres. In your flat white, that's roughly two and a half teaspoons — usually more than the dairy it replaced.
Almonds themselves are nearly sugar-free, so barista almond milk often needs a touch of added sugar just to behave like milk in a machine. A typical version sits around 2.5 grams per 100 millilitres — under one teaspoon in your cup. Often the lightest option on this list.
Barista soya milk usually contains a small amount of added sugar too, around 3 grams per 100 millilitres — just over one teaspoon in a typical flat white. Less sweet than oat, a little more than almond. And it brings more natural protein than either.
Order the identical flat white and just change the milk, and you can swing from under one teaspoon of sugar to around two and a half — without a single sachet, syrup or spoon involved. Recipes vary by brand, but the pattern holds: processing, not the plant, is often what adds the sugar.
Most oat, almond and soya milks also come in unsweetened barista versions, often with a fraction of the sugar and barely a difference in taste once it's in coffee. It's rarely on the board — but most places have it if you ask.
Start your transformation — try SugarCoach free, then £2.99/weekGeneral lifestyle education, not medical advice — personal medical decisions belong with your GP or pharmacist.