Supermarket milk always lasts at least a week, often longer and well past its date.
Milk from the milkman has a much shorter date and turns exactly on its date, I find?
Why is this? I used to out it down to it sitting on the doorstep but I've been bringing it in at 6:30 am lately and it's practically as cold as the fridge out there. Often I don't put supermarket shopping away for several hours, it doesn't seem to affect the milk.
I like having the milk delivered and I like the glass bottles but I don't like throwing away their very expensive milk. I'm thinking I won't be able to continue into the summer 
What's different?