I really think the substitution depends on what you're using it for. For example, in baking, I think you're generally using it for the acid, so would agree with the milk soured with vinegar. For other uses, like in a dip, creme fraiche might be far more appropriate.

I want to thank everyone who answered my query on making buttermilk. All your responses have gone into my "My Recipes" folder for future reference. As is usual in this sort of forum, responses often bring up further questions.

I, of course :-{) have one - Is it safe to assume that the vinegar to use would, in general, be plain "white" vinegar?

The suggestions to use 1 tablespoon of acid then add milk up to 1 cup is probably the best. It will give you the closest to real "buttermilk" in terms of the consistency and the flavor. I prefer the vinegar, since I find I can taste the lemon in the final product when I use that. Plus, using vinegar, I don't have to kill a whole lemon to get my acid. I find that crema, creme fraiche, sour cream and yougurt change the texture of my final product, especially in baked goods or pancakes.

I also keep a can of buttermilk "powder" in my fridge. The one I have is made by Saco (you can Google it), but I see King Arthur, which is an unimpeachable source for baking products, also carries their own brand. You dump in the amount of powder as instructed on the package, and use the same amount of water as you would have used of buttermilk. It's a fine substitute. The product is shelf-stable until its opened, and then can live in the fridge for quite a while. Most grocery stores around here have the Saco product. I think it's equally as good as the clabbered milk option. I usually do the latter when I have milk I need to use up, and the powder when I don't.

Really important when clabbering milk, by the way, to put it in the fridge after about five minutes, if you're not using it immediately. Otherwise, the curds you've created can get too big and hard. I can't get anything but 1% buttermilk, and so often I want a bit more butterfat in whatever I'm making, so I've been clabbering whole milk, frequently, lately and with good success. That said, I didn't have buttermilk once when making dinner rolls, and didn't have enough whole milk to clabber, so I used sour cream instead and the result was the recipe I eventually submitted to the dinner roll contest, which turned out to be a finalist. So yes, sour cream does work, in some cases. ;o)

According to the "Substitution Bible," you can substitute 1 c of buttermilk with:

* 1 tbsp lemon juice or vinegar + enough milk to equal 1 c (as a note for baking, let stand for 5-10 min)
* 1 c water + 1/4 c powdered buttermilk
* 1 c kefir
* 1/2 c plain yogurt + 1/2 c milk
* 1 c plain yogurt (thicker)
* 1 c sour cream
* 1 c milk + 1 to 1.5 tsp cream of tartar (for baking).

Joachim, David. "The Food Substitution Bible, 2nd Edition" (p.91) Toronto, Canada: 2010.

If you want non-dairy, add the vinegar or lemon juice (above) to a non-dairy "milk." If you want non-perishable, you can find buttermilk powder which is extremely convenient.

Creme fraiche also works. And depending on where the sour cream is intended, possibly Mexican style "crema".

There are a couple of good subs. I like to use yogurt or sour cream, you can thin it with a bit of milk if that works better for your recipe. You can also use milk with a Tablespoon of vinegar or lemon juice added. Add the lemon first into your one cup measure, then top off. Stir, let sit 5 minutes and use.