In the old days of mailmaids and wood chips, butter was the only thing left after the cream was turned into butter. Since refrigerators were not invented, the cream was left to sit at room temperature, where it attracted wild bacterial cultures that made the spice more palatable and gave the remaining butter a pleasant taste. At the beginning of the 20th century, modern buttermilk was invented that was large, rich, and, thanks to the industrial machinery, it is less likely to give food poisoning to humans. The "fresh and improved" buttermilk had nothing to do with the cream or butter – it was enriched milk enriched with lactic acid bacteria, such as yoghurt and kefir.
But you didn't come here looking for the whole history of butter. You're here instead, because your recipe needs buttermilk and, seriously, who keeps butter in the house? You may consult a few different packaging sites that you may be in, and some resources will tell you to stir milk and vinegar and let it sit for a few minutes. But now that you've read the first paragraph, you'll always know that vinegar infusion is false! The lie will lead you to biscuits and pancakes and fried chicken too oh, the shock of it all. If you make a recipe that requires buttermilk, it is a recipe that should not disappoint you. You deserve the best, so you will do well.
When you stimulate milk with something like vinegar or lemon juice, it triggers a chemical reaction between the previous proteins and the acid. Milk is made up of two different proteins: casein and serum. Casein is made up of innocuous molecules, and vinegar contains well-charged hydrogen molecules. Once assembled, those molecules quickly find each other and begin to rub their electrons with each other, and the casein proteins themselves form into large, white clusters called curds. Serum protein, also called Whey,
Buttermilk is what happens when milk is mixed not with acid, but with culture lactic acid bacteria, which is, or perhaps is, a type of virus. Bacteria consume naturally occurring sugar (lactose), converting it into lactic acid. When bacteria reproduce, they produce more acid, and as we learned some time ago, the acid causes the casein protein to decrease. However, unlike the restricted milk that has separated and dried up, when the selected milk begins to harden, it is quickly finalized to delay these bacteria to its appearance. If it was allowed to continue to be strong, it would be yoghurt. Can you see where this is going?
If you don't have butter, stir together one part yoghurt with two parts milk. Not only will you recreate that taste almost perfectly, you will also use the consistency of buttermilk, which is very important when making baked goods, pans, sauces, or dressings. In marinades and brines (such as those for fried chicken), lactic acid is essential for softening meat proteins – something that contains pure milk rings, which will not.
But wait, there's more! I know that when it comes to being included in the cooking area, sometimes you need to replace that. If you do not have regular yoghurt, you can use it three parts milk in one part of Greek yogurt (yogurt extract with extra water), or sour cream (It's actually yoghurt made with cream, not milk). Both will create a nice, creamy consistency that your recipe needs, with lots of delicious Tang.