Three Grain Sour Mash

[pope]

I'm starting a new cycle on a new recipe after a long time away, and I just did my first mash last night so I thought I'd put it on here and post a few updates as things progress. Maybe even post a few pictures if I remember to take them.

The recipe:

22.5# cracked feed corn
4.5# 2-row barley malt
3# rye malt
15 gal H20 (33% backset on successive batches)
Wyeast Bourbon Yeast (WLP070) starter (successive batches pitched onto active grain)

The method:

Bring water to boil, add corn and stir in, then rest until cooled to 152F. Stir in malts for conversion, let rest until below 80F, then dump into fermentor. Punch down grain cap for primary fermentation, strain liquid to carboy for secondary to let fine solids settle (I use a brew pump and a colander to get it into the carboy). Strip and recycle hot backset into next batch.

The yield:

At 85% efficiency, it would be a 6.5% beer.

I figured this would be simple enough that I'd actually do it. The first batch was a half batch to get the yeast going and my yield was horrible (8 brix/1.031 sg/40% efficiency), I'm assuming mostly because I started with 1/3 of the water because I can't read my own directions (and it was early). If anyone feels like chiming in, I'm curious to know your thoughts on whether or not I'll see additional conversion during fermentation. I'm expecting the acidity of the backset to help future cycles, and I may boil the corn for up to 30 minutes to aid in gelatinization, but I've done that before and constant stirring of porridge-thick corn is a very steamy workout with a high chance of burning if you miss a spot even briefly.

Aging is kind of off-topic for this forum but I have an 8-gal #3 char barrel from black swan which I'll be filling at about 62% abv.

Anyway there you go. If anything seems good/bad about the recipe and my assumptions, I'm all ears. Next update on total distillate yield from the first iteration plus brix and estimated efficiency on the second mash.

Final question - does anyone ever weigh their distillate? It seems to me this would be a more accurate method since the approximation of a gallon in a nearly full glass jug isn't exactly 128 oz.