Is there any buttermilk substitute?
If you’re looking for a substitute, check thirschfeld’s answer here: http://bit.ly/zl5tlh
Add 1 tablespoon of vinegar or lemon juice to 1 cup of milk and let it sit for a few minutes. Or, mix 1 cup of plain yogurt with 1 cup of milk.
The acid/milk trick works for baking, but if you want the buttermilk for a marinade (as for chicken) or as part of a sauce, it's not 100% equivalent. For baking, you can also find buttermilk powder (dehydrated buttermilk) that's shelf stable for just about ever. You add it in with your other dry ingredients, and use water for the liquid. But again, isn't going to work for marinating.
Yes..But as RobertaJ says the powder product is just fine. In fact it's more 'classic' in the acid balance than cultured buttermilk if you using it for a baking recipe. I will say the powder product should be frozen after opening to prolong its life and activity for baking. It works fine for me for marinating with rehydrating it with milk instead of water and making it a bit thicker (I just use my taste and eyes for that so it's not exact).