Grammar fix
turn
milk goes sour
If milk or cream turns, it becomes sour and is no longer fresh.
How oftenNow and then
LevelB2
Used inSpeech & writing
Hear it in context
Notice where the phrase sounds natural.
Don't put that milk in your tea—it's turned.
Our fridge broke down last summer, and by the next morning the milk had turned, so I had to go out for some before breakfast.
Fix the pattern
One small grammar move makes it sound right.
Not: The milk has turned off.
Say: The milk has turned. / The milk has gone off.
Say 'turned' on its own (or 'turned sour'), or 'gone off'. Don't mix the two.
Don't confuse it
Other ways to say it
Food is no longer good to eat
Which foodAny foodOne food
go badAny food or drink, UK and US. The safe default.be offHow British people say it at the fridge: "This milk is off."go mouldyWhen you can see mould: bread, cheese, fruit. US spelling: moldy.go staleBread, cake, biscuits, crisps: dry or soft, not dangerous.
turnYou're here · Milk and cream only, mostly British: 'the milk's turned'. Also 'turned sour'.