20C - Imperial Stout - Dark Matter

Style: 20C - Imperial Stout

I've made several imperial stouts, but this was the biggest and contained a stupid amount of grains. 10kg of pale malt plus specialty grains makes for an impossibly heavy brew bag. I had to come up with alternative solutions to get the grains out.

This recipe started off as an Old Rasputin clone then evolved from there. The current version is a streamlined malt bill with pale malt, black roasted barley, brown malt, and crystal 120. I added 500g of sugar at the end of the boil for an extra OG boost. Expecting around 9% ABV.

Pushing up to 9% and beyond becomes a logistics nightmare on a small BIAB system. It's like approaching light speed: the closer you get the more power it takes (we've all been there amirite??). As we push closer to 10% ABV the amount of grains required goes up, but at the same time the efficiency goes down, which means more grains, and so on.

Full recipe is on BrewersFriend, but here's the TL;DR
  • Brewday: 2018-10-21 (brew 1 of 2)
  • Malts: 2-row pale, Brown, C120, Black Roasted Barley (500L)
  • Hops: [Magnum] (Nugget/Centennial)
  • Yeast: SafAle S-04 (3rd generation yeast slurry)
  • OG: 1.087, FG: 1.014, ABV: 9.6%
  • Kegged: 2018-11-17 (+28)
Specialty malts: crystal 120, English brown, Black Roasted Barley. Under this layer is 10kg(!) of base malt. Note the full 5G bucket.

Crush. It was too much malt for the bucket I was milling into so some had to go in a 2nd bucket. This is getting ridiculous. 

Plenty of water for the mash. Probably could have gone higher for a looser mash.

Mash temp

Brewery Manager Princess Kevin

This is the first time I've attempted to lift the grain bag and gone: NOPE. That's not moving. Not without a hydraulic engine crane. So I drained most of the wort into a 3rd kettle, moved the mash tun to the floor where I could get some decent lift, then transferred to my sparge kettle. 

After transferring grain bag. My back hurts.

Once past the whole 'removing grain bag that probably weighs more than me' part, it's pretty much business as usual. Heat wort to boiling, and add hops.

OG boost via 500g of sugar. This was about 4% of the total sugars. Sugar will lighten the body a bit and add a couple of points to the OG which in the end will put it closer to 9% ABV. 

120g of Nugget and Centennial added for 5 min, then on to chilling

Terrible efficiency around 54%, but managed to hit 1.087 (adjusted from brix)

Wort sample

Into the fermenter. Not even messing around with an airlock. Big Beers get a blow-off. This will hang out in the fermenter for 1 month before kegging to make sure the yeast has plenty of time to do its thing.
Few hours later: give a listen to the blop-blop-blop in the blow-off jug.

2018-10-24 (+3) - violent fermentation has subsided. stuck an airlock on and dumped the blow-off. Still going, but has slowed quite a bit.

2018-10-26 (+5): already down to 1.012 (!) which gives us 9.8% and it will probably drop a bit more over the next couple of weeks. Still some time to go in the fermenter but it's mostly finished. Smells like chocolate and tastes smooth with no booziness even after 5 days. Looking really murky but that will settle out.

UPDATE: checked again about a week later (+12) and FG hasn't moved so it should be finished coming in a hair under 10%. Looks about the same. Starting to think about oak and bourbon.......

2018-11-11 (+21): transferred to secondary so I could use the yeast for an Oatmeal Stout. Looking nice and dark!

2018-11-12 (+22): stole a sample and the refractometer check came out to brix 10/1.014; which works out to about 9.6%. Attenuated more than I expected but it's tasting nice already.

2018-11-14 (+24): into the fridge for cold crash

2018-11-16 (+26): Fresh kegged sample, no carbonation yet

2018-11-18 (+28): carbonated sample. tasting nice. dark chocolate and coffee. firm bitterness. lots of hop presence for an Imperial Stout.

2018-11-18 (+28): what's all this? charred oak spirals?

...Soaking in Wild Turkey 101 Bourbon??? To be continued....

2018-12-20 - oak/bourbon Update:
I haven't been brave enough to dump the oak spirals or oakified bourbon into the keg, however... myself and some brave testers have been dropping the liquid into individual samples which lets us determine how much extra flavor we want to add. If I can nail down exactly what I'm looking for - a light hint of bourbon and oak - then calculate for the remainder of the keg, then I'll add it. Until then we'll just keep testing. For Science.

Note: Dark Matter is tasting fantastic with and without the oaky bourbon! It's deep and complex with some dark roasted coffee character and dark chocolate. The hops are present but not overpowering. I'm really liking Nugget as a Stout hop since using it exclusively this past summer in an American Stout.

2018-12-29 (+70) - oaked bourbon sample. This is what I decided to go with: the mix-your-own BA stout. 4 or so drops in a small sample is about right. The oak and bourbon add some layers of complexity to what I think is an already solid imperial stout.