My SIL and I were talking and trying to figure out what the purpose of apple cider vinegar in a pie crust recipe is for. I looked through my reference books and didn't find anything that directly talks about this. It didn't even mention cider vinegar in crusts. I did see one blurb that said about cider vinegar itself: "Apples are rich in malic acid, so cider vinegars undergo a malolactic fermentation that may augment aroma while softening acidity."
So could I'm thinking that that would in turn do the same for pie crust, in apple pie? Or is there a different reason??