Serious question, I swore I would never put vinegar in my pie crust until a baker in Tulsa handed me a slice
I always thought a splash of vinegar in the dough was some old wives tale, but after 3 failed batches of hockey puck crusts last month I tried 1 tablespoon of apple cider vinegar in my usual recipe and the crust came out flaky enough that my husband asked which bakery I bought it from, so now I want to know if anyone else does this or if it only works with certain fats.
My grandma used to put a capful of white vinegar in her pie dough back in the 70s and I always thought it was just a weird habit from growing up poor. Then I started noticing the same trick pop up in dumpling wrappers, biscuit recipes, even some pizza doughs, and it hit me that folks have been sneaking acid into dough for way longer than any of us think. The vinegar slows down gluten just enough that the dough stays tender instead of turning chewy, which is why your hockey pucks turned into bakery crusts. Works with butter and lard in my experience, though I use a bit less with shortening since that stuff already makes things flaky on its own.