[masraum]

I asked my mom (Southern Girl) about vinegar pie. She said that she'd heard of it, but can't remember if she'd ever had it. She has had "Chess Pie". Vinegar pie is, apparently, a type of chess pie. What I've read is that some (seems most) chess pies have an acidic ingredient which is usually one of three things, vinegar, buttermilk or lemon juice. Here's part of a web page that I found talking about chess pie vs buttermilk pie.

To put it simply: All buttermilk pies are chess pies, but not all chess pies are buttermilk pies.

The chess pie originates from England, but has long been known as a traditional Southern dish.

Chess pie was created using four basic ingredients (flour, butter, sugar and eggs). Recipes vary depending on the time period in which they were created. “Many people likely just used what they had on hand during the time when the chess pie was gaining popularity, and buttermilk was a common pantry staple,” Southern Kitchen’s chef Jeffrey Gardner explained. “After reading through one of my older cookbooks, it's important to note that while most chess pies — especially the ones we see today — have dairy in them, some do not. Cornmeal as a stabilizer in the filling is distinct to chess pie.”

Buttermilk is the main factor in differentiating the two pies. Adding an acidic ingredient, like buttermilk or vinegar, to the pie will cut down on the sweetness and change the consistency of the filling. More specifically, these ingredients affect the cooking of the eggs. Gardner explained: “Acid lowers the temperature at which eggs, and egg whites in particular, coagulate. There is a delicate balance between [adding] enough acid to strengthen the protein bonds of the eggs and [adding] too much acid, which prevents coagulation [completely]. The short answer is that [using] the right balance of acid … means that the eggs will coagulate — or set up — more smoothly.”

As I started telling my wife about them, she realized that my M-i-L makes a chess pie.

My mom also mentioned "shoofly pie". I'm pretty sure I haven't had it, but it sounds really tasty. It's basically a molases pie.