I had an idea a while ago to make a very large Imperial Stout (18-20%), but I have an egregious number of questions.
Has anyone had any experience with this type of Brew? If so any tips?
I know I need to pitch two types of yeast, but I have 9 lbs of Dark LE and 3 pounds of Light LE, along with 2 lbs of Candi Sugar to add during fermentation and other malts and sugars to add during to boil. Is there such a thing as TOO dark? Will it be too roasty with that much DLE?
A guy in the forum here made a 20 or 25% barley wine I got to try at NHC a couple years ago and, considering the novelty, it was pretty good. I believe the trick is to start off high gravity and get the yeast going and continue feeding the yeast sugar and very high gravity wort and aeration. You will also need a yeast that can tolerate the high ABV as most brewers yeast can’t go much above 12.
Anyway, good luck, it is definitely an advanced technique. I’ll PM him for you and ask him to chime in.
Sean Paxton brewed the dogfish 120 clone for can you brew it a few years back. I don’t remember the schedule, but he pulled about a half gallon off of a 10 gallon batch every so often to whisk in corn sugar. He would then pour it back in to the fermenter. He mentioned that he wouldn’t have tried it without a conical as it would have been a big PIA without the racking port.
You definitely need to pitch huge, add nutrients and oxygenate a few times early in fermentation to keep those yeast happy. Most people suggest constant feeding rather than adding everything up front. That seems to be a necessity in making these huge beers. I would also consider degassing the beer several times through the extended fermentation to help make the environment less hostile to the yeast.
Typically, I’d say throw all the sugars in the boil but for something this high, I agree that incremental feeding might be the way to go.
If you’re using all that LME, I’d try to start with an initial wort that’s extremely fermentable. Low mash temp for 90 minutes or so.
And, no I don’t think you can go too dark. I have no idea how roasty it will be as no one knows whats in dark extract, but you can be too roasty. I think the bigger risk is too sweet with that much dark extract.
Re aeration, I think you would be better off with a mix stir rather than an aquarium bubbler. I haven’t ever seen anything scientifically-based that indicates aquarium bubblers are a good way to aerate wort. You will have to use a vessel with a relatively wide mouth to use a mix stir like a bucket or big mouth bubbler.
I use my mixstir in a better bottle all the time. Used it in a glass carboy as well. I actually prefer it because as it spins up the wort doesn’t fly over the edge as it has before in a bucket.
you don’t have to wait till you are all grain but I would skip the dark LME in favor of the lightest colored DME you can get your hands on. dissolve it in enough water to pour.
Dark LME has a lot of unfermentable sugars in it. if you add a lot of that to a big beer you will end up with a very very sweet final product. like really grossly sweet. you might like this but in my experience it’s not very nice. lighter colored extracts tend to be more fermentable because the maltster used mostly base malt to make the wort that was concentrated into the extract. Simple sugars help here (cane sugar, beet sugar, candy sugar) because they are 100% fermentable and will lighten the body and cut the sweetness some. but skipping the dark extracts will help even more.
To do this with extract I also would recommend using a lot of light extract and much less, if any, dark extract. You can get all the roastiness you need by steeping specialty grains. The dark candi syrup will add plenty of color while being 100% fermentable. What are you doing for yeast?
EDIT: I knew a lot of people who fit the “Big Alcohol, Little Knowledge” category
Okay, I did the math, if you want ~20% ABV you will want to start around 1.180.
if you do incremental feeding and you start at 1.075 with 2 gallons then add 1 gallon @ 1.200 when it’s about 1.040 and another 1 gallon @ 1.250 when it’s down to about 1.040 again and then a final gallon @ 1.250 when it get’s down to 1.040ish again that gets you an effective OG of 1.170 and if you can get that to finish down at 1.020 you will have a ~20%abv beer. and the actual gravity at each step is never super high so the yeast stress is reduced.
effective OG real gravity after addition abv after addition
1.075 1.075 0%abv
1.116 1.093 3%ABV
1.149 1.092 7.5%ABV
1.169 1.092 11.5%ABV (pitch your super high gravity yeast here. pitch lot’s and lot’s of it.)
My bad. I assumed you were mashing some grains and then adding all the extract and sugar to boost the alcohol as it fermented. You don’t need to go all grain, you could do a mini-mash and then add extract. Or you can stay with all extract, if that’s where you’re comfortable.
For extracts, I have found Breiss Pilsen dry extract to be highly fermentable and I would recommend it for this application. Something like their golden light might give you more body. I would definitely steep some dark grains for color and flavor.
As far as you’re target ABV, what batch size are you looking at? IME, you’re not likely to get 20% ABV with 12 lbs of liquid extract and a couple lbs of sugar, unless it’s a smaller batch. I haven’t plugged this into a calculator, but I think you’ll need more extract to reach that % and still have a stout.