For my first mash I made a wash of 80% corn and 20% barley with and OG of 1.065 (Ian Smiley' recipe). My wash has almost completed fermentation and I plan on doing a sour mash. I could do the method of UJSM method of 7lbs corn, 7lbs sugar and the backset from the first mash. I'm looking at doing a different kind of sour mash and wonder if this would work. I could do a beer stripping run on the first mash and take the backset and use it in a completely new mash (using the backset and water as the liquid for the second mash) using the same recipe I started off with. The reason I thought of this is that I want an all-grain product. When performing the UJSM method in the second mash you are essentially using three different things from your first mash: yeast, spent grains and backset. Well you can pitch new yeast rather than using the old yeast (I've been a homebrewer for many years and this is just repitching onto a yeast cake), the spent grains (which you aren't really going to be getting anything out of) and the backset. So by just using the backset to make a second mash this will essentially be a sour mash, right? I'm curious to see what the mentors think about this.
To be clear this is what the recipe would be for the second mash (this would be a conversion mash just like the first one):
4.5 gallons water
1.5 gallons backset
On a separate note, what type of sour mashes do Bourbon and Tennessee distilleries use? A method like UJSM or a method more like the one I described?