AG# 48 Chocolato Imperial Stout

[charliemartin]

Been planning this one for a while now. A big RIS about 10%+ abv. Wasn't too sure about what efficiency I would get so estimated 60%. I ended up with about 13 litres @ 1.120 according to my refractometer. Liquored back to 15 litres and got 1.106ish. Quite hard to read exactly on the refractometer. I think it may be down to the darkness of the wort as I don't normally find it that difficult to read. However, I took a gravity reading with my standby hydrometer which gave a reading of about 1.114-1.116!!!
Not sure which one to believe, but don't suppose it will make much difference at the end of the day. If the yeast can manage to do a half decent job of fermenting this one it should be over 10% abv as planned.
The wort was the sweetest tasting wort I have ever tried. Even with a decent level of bitterness to counteract it, it was sickly sweet and that's coming from someone with a very sweet tooth. I suspect the beer will need a fair bit of ageing to get the best out of it.

I also brewed up a demijohn of wort from a second batch sparge of about 10 litres. This gave me a pre-boil gravity of 1.024 to which I added 200 grams of Demerara sugar. Post boil I got about 4.5 litres @1.064. I pitched 3.5g of SO4 yeast to this.


Chocolato Imperial Stout

Date: 03rd May 2016

Gyle Number: 48

Fermentable Colour lb: oz Grams Ratio
Castle Chateau Pale Ale M 4 EBC 13 lbs. 3.6 oz 6000 grams 73.2%
Demerara Sugar 20 EBC 2 lbs. 3.3 oz 1000 grams 12.2%
Chocolate Malt 1060 EBC 1 lbs. 5.1 oz 600 grams 7.3%
Flaked Oats 0 EBC 0 lbs. 14.0 oz 400 grams 4.9%
Weyermann Carafa III 1400 EBC 0 lbs. 7.0 oz 200 grams 2.4%


Hop Variety Type Alpha Time lb: oz grams Ratio
Challenger Whole 7.12 % 120 mins 0 lbs. 2.8 oz 80 grams 61.5%
Northdown Whole 6.52 % 120 mins 0 lbs. 1.4 oz 40 grams 30.8%
Challenger Whole 7.12 % 30 mins 0 lbs. 0.4 oz 10 grams 7.7%
Cacao Nibs 30 mins 25 grams
Vanilla Bean Extract flameout 1 teaspoon


Final Volume: 15 Litres
Original Gravity: 1.104
Final Gravity: 1.029
Alcohol Content: 10% ABV
Total Liquor: 29.7 Litres
Mash Liquor: 21.6 Litres
Mash Efficiency: 60 %
Bitterness: 82.6 EBU
Colour: 389 EBC

Ferment with WLP007 (Dry English Ale) (1 litre starter, then stepped up to 2 litre starter)

Cheers,
Charliemartin

Grist (minus oats)


Mash Tun at the Limit


First Runnings


The Boil


OG

[charliemartin]

Bottled this today. Finished pretty high at 1.030! That is 71.7% apparent attenuation which is probably not bad considering the strength of this beer. I had hoped it would go a few points lower, but I think the yeast must have simply run out of steam once the alcohol level got up above 9%.
Primed with 36g of sugar for 14 litres. Hopefully the yeast still have enough oomph left in them to carbonate the beer, but not enough to keep munching and turn them into bottle bombs.
Plan to leave the bulk of these for Christmas. Whether that will be Christmas 2016 or 2017 remains to be seen.

[gaunt_paul]

This one looks great. I recently made a similar beer, with a slightly lower gravity (a mere 1.111!), also using WLP007. It gave up at 1.030 as well. I reckon it did well to get that far!

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[charliemartin]

This one looks great. I recently made a similar beer, with a slightly lower gravity (a mere 1.111!), also using WLP007. It gave up at 1.030 as well. I reckon it did well to get that far!

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I'd forgotten about my hydro reading! I logged this brew as 1.106 which was the refractometer reading.
I also discovered an alternative formula for calculating abv, which is supposed to be more accurate for high gravity beers. Even using 1.106 as the OG, it calculates the abv as 11.2%!!!
I think it was a good idea to use 330ml bottles.
Interesting that the WLP007 stopped at 1.030 in your beer too.
Have you tasted it yet?

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[gaunt_paul]

It's already quite tasty, though very sweet. It'll need some time for the flavours to meld together. I'm hoping it'll be a cracker in time for this winter

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[charliemartin]

I have kept a stash of this beer in the shed for almost 5 years now and tasted a bottle from time to time. It never carbonated unfortunately. I tried re-seeding in Feb 2017 using a starter made with S04, but probably didn't add enough as only a couple of bottles carbonated at all.
However, on 13th Feb 2021 I re-seeded with a starter of Voss Kveik and 9 days later tested a bottle. Lo and behold it has finally carbonated. It makes such a difference to the beer. You would never know it was almost 5 years old. Very nice, dark chocolate, a touch of liquorice and a kick like a mule.
Couldn't drink many of these without turning into a gibbering wreck.

[floydmeddler]

Amazing! I love reading 'big beer' posts that give updates years later. I do an 8.5% chocolate oatmeal stout. A corny lasts me around 3 months. I never get to try it years later!

I am planning a big brute of an English barleywine and plan to age it in demijohns for a year. I'll be able to keep my mits off it then

I'm looking forward to the 10 yr update 'God' spare us!