Sour Dubbel on Plums

Today we're doing a group brew for our 15 gallon sour bourbon barrel. This is our fourth fill overall for this barrel, so it won't have dominate bourbon flavors, but we're likely to still pick up some oak. The beers that have gone in this barrel so far:

1. Imperial Stout (Get Out Stout)
2. Imperial Porter (Chasing Abbey)
3. Golden Sour (BJRR Golden Sour with Coffee)

The recipe we're brewing today is inspired by this one from the Mad Fermentationist. We're doing some slight modifications for our version, such as grain substitutions. One that I'm kind of excited about is we're using malt from Solstice Malt, Utah's first maltster since the 1960s. After the souring that will take place during barrel aging, we'll put this beer on plums. Here's the beer as we're brewing it today:

This recipe is for 5 gallons. Our total batch size is 15 gallons, so this recipe 3Xs.

Target OG 1.058

10.0# Solstice Pale Malt - Genie

1.0# D-180 Belgian Candi Syrup (secondary, at barrel filling)

0.5# Simpsons Double Roasted Crystal

1.5 oz Aged hops (60 min)boil

Whirlfloc

Yeast Nutrient

WLP545 Belgian Strong Ale

Mash at 158F, 90 minute boil, ferment at room temp.

Brewing Notes
No major issues, but a couple of minor ones. First, I'm not sure if the Solstice Genie is less plump than the base malts I usually use, or maybe my mill was just having issues, but on the first pass there were quite a few uncrushed or barely crushed grains. I ended up fiddling with the gap and ran the grains through a second time and it worked well. It's probably about time to disassemble the mill and perform some maintenance.

We basically did one ten gallon batch on my system followed by a five gallon batch on my buddy's system. The 10 gallon portion came out with an OG of 1.064, and the remaining five came out at 1.055.

Update 10/8/2018
I pitched the yeast last night around 7:30PM and fermentation is very active this morning. I was hoping I could get away without using a blow-off, but I'm afraid I'm going to come home to a mess tonight if I don't.

Update 10/10/2018
Thankfully, this batch never had a messy blow off. As of this morning, the Tilt I put into one off the three fermenters is reading ~1.008. I'm kind of blown away that this yeast was able to tear through the sugars as fast as it has.

Update 11/17/2018
This beer was racked into the barrel today to begin the souring process. The Belgian Candi Syrup was added first, then the beer was racked on top of it.

Update 3/6/2020

We tasted the barrel beer a couple weeks back and determined it was ready to go on fruit. I didn't check pH, but the beer had a very pleasant sourness; definitely a barrel aged sour, but not over the top acidity. We have 25.5 pounds of Utah-grown plums that we acquired last fall that were washed, pitted and quartered, then frozen until we were ready for them. I started thawing them the evening of 3/4/2020 and transferred them (still partially frozen) to a 15.5 gallon Kegmenter last night, where it will age until bottling. I've mentioned before, I'm not a fan of home-pasteurizing fruit as I think you lose fresh fruit character, so I prefer sanitizing with potassium metabisulfite. In this case, I used 1/2 teaspoon potassium metabisulfite dissolved in 1/2c RO water. This was poured over the fruit in the Kegmenter last night (3/5/2020) and the barrel beer will be transferred on top of the fruit tonight.