Imperial Stout

I usually make some crazy ass stout around mid-to-late October to be drunk by the holidays. While this usually works out decent, I noticed when I boosted the abv to 8% or higher, the beer wasn’t ready in time. Big beer needs aging. It took me a while to come to terms with that and really start planning ahead ― even if that means brewing in 100F degree weather in July to have something ready by November. Brutal.

There were a few things I wanted to do for this to help aid in the drinkability factor. The first thing was to minimize the tannins and roast burnt flavor than can come with these, and the second was to try and dry it out a hair more than normal. To minimize the roast flavor, one should add the dark malts at vorlauf or even better, do a cold steep with the grains. For this I opted to add the dark grains at vorlauf.

There are a few ways one can try and dry out the beer:

1. Mash in low (146F-150F). This will ensure a more beta-amalyse conversion, which will result in more simple sugars. Yeast loves that shit. I did not do this though for some reason looking at my notes, but it’s a good idea.

2. Adding corn sugar in the boil or at high krausen. Corn sugar is essentially glucose, and yeast consume those sugars first before consuming the longer sugar chains. The potential issue with adding corn sugar in the boil is that the yeast may rip through that first and tire out, leaving too much residual sweetness and an under-attenuated beer. As a result, I opted to add the corn sugar at high krausen along with some more yeast (though the added yeast may not be needed). You do not need to oxygenate fully after adding those items ― a light swirl should be enough.

3. Adding Beano®. This is a dietary pill that has an enzyme that can break apart longer sugar chains the yeast can’t access. I used it for my Champagne-style beer and it worked well.

There is a way to boost the abv in a beer, which is slightly different yet related. Drying beer out you are trying to drop the gravity to get rid of the sweetness (which does boost abv some of course), however adding more complex sugars will boost the abv as more alcohol will be produced, yet the gravity may not drop down. Here is great article on how to feed big beer to boost the abv.

The final step to this is “properly” bottling the high alcohol beer. Anything above 8% (or low pH especially combined with a higher abv), the yeast can struggle in the bottle naturally carbonating. A way to help ensure the bottles carbonate is to take some fresh wort and some of the fermented beer (at a ratio of 1:1), add some fresh yeast, then let it acclimate for a few days in that harsher environment. From there you can bottle with that starter you made along with your normal fresh priming sugar amount. The amount I have been doing is 15 ml of each of fresh wort and fermented beer I want to bottle with per 1 gallon. The amount of yeast I just eye ball (a little sprinkle of dry US-05 has been working for me). The 15 ml amount I came up with came from this paper by Matt Bochman, which I did not read, but listed to him explain it here.

Video of the brew day:

Recipe:

Batch Size: 1 Gallon
OG: 1.116
SRM: 50
Est ABV: 11%-ish
IBUs: 75
Boil Time: 90 Min

Malt:
2.75 lbs (65.5%) – Maris Otter
6.5 oz (9.5%) – Caramunich
4.5 oz (6.7%) – Flaked Barley
3.5 oz (5%) – Acid Malt (because of my water)
3.0 oz (5%) – Crystal 60L
2.0 oz (3%) – Chocolate Malt (added after conversion)
1.5 oz (2.5%) – Carafa III (added after conversion)
2.0 oz (3%) – Corn Sugar (added during fermentation)

Mash:
155F for 70 Minutes

Hops:
.15 oz (45 IBUs) Columbus (14% AA) @ 60 Min
.15 oz (8 IBUs) East Kent Goldings (5% AA) @ 15 Min
.15 oz (21 IBUs) Chinook (13% AA) @ 15 Min

Yeast:
US-05 slurry

Here’s what went down:

Brewed 7/8/17

7/10/17: Activity is going, but not strong.

7/12/17: Added 2.0 oz (3% of the grist) of dried corn sugar and a little US-05 dried yeast…maybe an 1/8th of a pack at the most.

7/23/17: Gravity at 1.040. It’s a bit too high for what I wanted. Lightly swirled the yeast back into suspension to hopefully get a little more fermentation out of it. I would be ok if it finished closer to 1.030. At 1.040 it would still be a 10% beer though.

8/2/17: Gravity still at 1.040. Transferred it to a secondary and added half a crushed tablet of Beano®.

8/19/17: Gravity still at 1.040. Ugh. Fine. Took 15 ml of the finished beer and 15 ml of fresh wort, sprinkled in some US-05 to make a bottling starter.

8/22/17: Bottled with the starter I made and with .2 oz corn sugar (I only had half a gallon left at this point due to testing and transferring).

9/10/17 Early tasting:

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