Have you ever started a baking recipe only to find that you need buttermilk and you, of course, don't have it? The only people that I know that keep buttermilk in their fridge are old southerners. But no worries because it can be made instantly. All you need is milk and a lemon.
Add 1 1/2 TBS lemon juice per cup of milk and let sit for 5 minutes. Viola! There you have buttermilk and it can be used to replace buttermilk in any baking recipe.