If you are like me I don’t keep buttermilk on hand. I do use it a quiet a few recipes. When I don’t have buttermilk I “make” my own. To make 1 cup of buttermilk you will need 1 tablespoon of lemon juice (you can use vinegar but I havn’t tried it before) then enough milk to make 1 cup.
I use to add the lemon juice first to a liquid measuring cup and then add the milk but it work a lot better if you first add half of the milk, then add 1 tablespoon of lemon juice. Last fill the measuring cup with milk until if reaches the 1 cup mark. It seems to have a better consistence when I mix milk-lemon juice-milk verses lemon juice then milk.
Let sit for 5-10 mins. I use skim milk and it works great but the more fat the milk has the creamy the buttermilk will be.