Thanks so much!!
Haven't used it, but from what I gather it should be thicker and tarter than regular buttermilk. Yogurt cultures are used to produce it, and it's fermented at a higher temperature so is more acidic.
That was exactly my concern (the acidity) . . . so much to learn. Would love to hear other cooks' experiences and lessons learned. Thanks! ;o)
I've been researching this question, and can't come up with a solid answer, but here's my idea. Rose Levy Berenbaum (in her wonderful Cake Bible) says this: "I prefer not to neutralize the flavor of buttermilk with baking soda, as I find the taste fuller and the texture finer using baking powder alone." and "It is preferable to use too little baking soda rather than too much." I think (if you're in an experimenting mood) I'd just substitute one for one. If the Bulgarian buttermilk is really thick, maybe thin it with a smidge of regular milk. Hope someone else has more specific advise for you!
I don't know about Bulgarian buttermilk, but i buy Bulgarian yogurt all the time. It has no fillers or stabilizers so it is very runny. I wonder if this is the same for your buttermilk? I don't really know if buttermilk has any additives but I use Bulgarian yogurt exactly the same way I do plain yogurt and it works fine. When I made home made yogurt, it seemed to be just like the Bulgarian yogurt I buy.