My great-grandfather was famous in the family for making "pasties" a type of Cornish savory pastry filled with meat and vegetables that was the traditional food of miners (he came from a Cornish mining family, so that's why he knew how). I recently got my hands on his recipe for pastry crust. It calls for egg, which I didn't expect. I am quite the prolific pasty-maker (and other pastry-maker) myself but I use only fat (half lard and half butter), flour, salt, and water in my pastry (well, and sugar if it's a sweet pastry.) I'm wondering what the egg is for. Does it make it brown better, like an egg wash? Do the egg proteins toughen the pastry a little? I was thinking this might be the case and, for miners who ate their lunch in one hand down in the mines, it might have made sense to have a slightly tougher, less fragile crust. But, for those of us who have the luxury of eating our pasties at the table, it's not necessary. Has anybody made pastry with egg and what are the pros and cons? My interest is piqued.
Also, there is a bit of vinegar in his recipe. I've seen recipes that call for vinegar before but I've never tried it. Does it just add flavor or is it a textural thing? I would think most of the acetic acid would cook off during the baking time.