High Gravity Question(s)

[Gytaryst]

I like big (11% to 14% abv) bourbon-barrel imperial stouts. I gave up home brewing for a number of years, but I'm getting back into it on a limited basis - to brew (big) imperial stouts. I've had these questions for years. I've done countless hours of searches and have come up with a wide variety of answers. The problem is; if you ask 10 people the same question and get 10 completely different answers, you really haven't gotten an answer. 1 of those 10 might be the correct answer... but if you don't know the correct answer, then how do you know which of the 10 answers is correct - if any?

So my questions.

I haven't been able to find any clear cut way to know how much, (if any), aging in a bourbon barrel adds to abv. I'm assuming it's not much. I realize there are a billion factors involved. But assuming the barrel is relatively dry after the bourbon is dumped, and no additional bourbon is actually added to the beer???

The bigger question I had was the high gravity. As an example, Goose Island Bourbon County Brand Stout is usually around 14% abv.

1. Does that mean the beer they are putting into the barrel is 14% abv?

2. What yeast, or what techniques are commonly used to get a RIS to 14% abv?
Thank you in advance for responding. I haven't done (extensive) research on this. Whenever I do sit down and try to research it I end up getting frustrated with so much (seemingly) different information. I tried to brew a couple of 12% beers back in the day, and neither one of them turned out. The final gravity never dropped to where it needed to be. I know there could have been a million reasons that contributed to that also.

 

[tracer bullet]

An actual barrel could soak up and evaporate out water, and ABV may be higher. I couldn't try to estimate that one but that would be the only way for the ABV to continue to rise. Well outside of errant yeast turning it into a sour beer and fermenting deeper, but that's generally an accident and not likely what you're thinking about.

High ABV is basically a yeast that can hack it (S-05 is often discussed, but there are others) along with optimal conditions (a large yeast starter, warmer temps especially towards the end of fermentation (like 70F not 80F).

 

[Mr. Vern]

I haven't been able to find any clear cut way to know how much, (if any), aging in a bourbon barrel adds to abv

Interesting question!

I assume they are adding a little "estimated ABV" to the beer being aged, especially with the ABV = Value mentality. Marketing will have a hard time overlooking that.

I read there are a lot of strains that will get you there, but a handful seem to be most common. Overpitching or having a fresh yeast cake is not a bad idea, extra efforts into O2 and nutrients are a must IMHO.

Here is a long video breaking down all-grain recipes for award-winning (homebrew) Imperial Stouts at around the 12 minute mark you will see all of the yeasts used in the recipes tallied. The key is yeast health and quantity.

I am planning a huge RIS brew day myself, searching HBT can be tedious but the treasure is there to find. I will be doing a dry Irish stout for my starter this weekend . Cutting it close to Pattys day!

 

[VikeMan]

I haven't been able to find any clear cut way to know how much, (if any), aging in a bourbon barrel adds to abv. I'm assuming it's not much. I realize there are a billion factors involved. But assuming the barrel is relatively dry after the bourbon is dumped, and no additional bourbon is actually added to the beer???

Very little. IMO not even worth thinking about, especially with large barrels, unless the barrel has visible liquor in the bottom before filling.

The bigger question I had was the high gravity. As an example, Goose Island Bourbon County Brand Stout is usually around 14% abv.

1. Does that mean the beer they are putting into the barrel is 14% abv?

I would bet yes. Unless they are actually adding bourbon.

2. What yeast, or what techniques are commonly used to get a RIS to 14% abv?

Use a yeast with high ABV tolerance. And if you are adding simple sugars to the fermentables, consider "feeding" the fermentation with those sugars gradually.

ETA: Many (most?) strains can go higher than their published ABV tolerance if pitching a large enough, healthy pitch.

 

[McMullan]

What yeast, or what techniques are commonly used to get a RIS to 14% abv?

My advice is brew a batch of regular beer around 1.050 then harvest and repitch the whole yeast cake into the imperial wort. Or just dump the imperial wort on top of the fresh yeast cake. If the recipe includes brewing sugar(s) to boost gravity, add it all at the beginning. Barley worts are more complex than other fermentable liquids, especially in terms of fermentable carbohydrates. The yeast consume them in a predictable order (easy to not-so-easy to metabolise) and you don’t want to divert their metabolism away from ‘downstream’ carbohydrates by tossing in dextrose/glucose later in fermentation. The yeast are going to be key so repitch fresh, use yeast nutrients (including zinc) and oxygenate the imperial wort before pitching. With enough fresh yeast in good shape, you can choose from a number of tolerant brewer’s yeast. I quite like WLP007 for imperial beers. Don’t worry too much about listed alcohol tolerance numbers. The yeast cells are going to drop out at a rate as ethanol levels get high. So as long as enough yeast get pitched, it’s not a problem. They don’t all just simply drop out at a specific alcohol level.

 

[Gytaryst]

Thank you. Sounds like solid advice. Healthy yeast, lots of it, yeast nutrients, and oxygen. I used to wash the yeast from the yeast cake and keep it going way back when, but I brewed a lot more back then. I would love to do that now, but I don't plan on brewing quite as often. The price of ingredients has gone stupid since I last brewed.

I appreciate the comments. I think I'll grab a yeast and just stick with that for 4 or 5 brews to see what happens.
I brewed what was supposed to be a 12% Belgian Quad way back when. I remember I spent around $80 on ingredients and thought that was outrageous. That's about what it costs to brew a session beer now. My OG was shorter than I hoped for, and FG was substantially higher. If I remember right it came in at around 4.8% abv. It was the only legitimate drain pour I ever brewed. My wife said she could use it for shampoo - but then decided it was WAY too sticky. It was some of the best fertilizer I ever brewed tho.

Thanks agin guys. Greatly appreciated

 

[Bobby_M]

I would say the hardest thing is getting the balance right. Between the yeast die off at high ABV, the lesser fermentability of darker grains, the general limits of attenuation, etc, Lower mash temps for longer rests to help break dextrines down, big starters or pitch a lot of dry yeast. It's far better to ferment a bit too dry and then bring in maltodextrine or lactose support at packaging than to try to dilute down a cloying sweet mess. Temp control is also touchy. A beer exceeding 10% ABV with the appropriate gigantic yeast pitch is going to rocket the fermenter's internal temp at least 10F above the ambient environment. You want to keep the wort/beer temp in the high 60's

If you're brewing with extracts and can't manipulate fermentability with a step mash schedule then you'll want to add some table sugar to boost alcohol without dextrines.

You asked about what yeast... Almost any yeast can get you 14% if you pitch enough. I just fermented a stout to 12% using Omega West Coast 1 at about 100B cells per gallon of wort. That was a 4 liter starter for 8 gallons of wort. You can also get it done with Nottingham.

 

[mac_1103]

It's far better to ferment a bit too dry and then bring in maltodextrine or lactose support at packaging than to try to dilute down a cloying sweet mess.

This is nice to hear coming from you. My Christmas stout came in way too dry, and the 65 IBU I had put in there to counteract the residual sweetness I was expecting wasn't working at all. But a little bit of unfermentable sugar added at the end turned it into a really smooth (and way too easy-drinking) beer. So I won't apologize for the cheat, and I think I just might pour myself one right now.

 

[Bobby_M]

This is nice to hear coming from you. My Christmas stout came in way too dry, and the 65 IBU I had put in there to counteract the residual sweetness I was expecting wasn't working at all. But a little bit of unfermentable sugar added at the end turned it into a really smooth (and way too easy-drinking) beer. So I won't apologize for the cheat, and I think I just might pour myself one right now.

Course corrections and blending are in the master brewer's toolkit.

 

[mac_1103]

I'm just glad the master brewers let us mere mortals borrow a tool once in a while.

 

[VikeMan]

I'm just glad the master brewers let us mere mortals borrow a tool once in a while.

 

[hottpeper13]

+ 1 on the Notty,it's my goto for RIS. Think BBQ,low and slow, I do 148* 2 hour mashes. To get to 14% you need around 1.135 SG or more,that gives you an intense fermentation with any yeast but with Notty I put 4 gal of wort in 2- 6.5 gal Big mouths and this last batch krausen got all the way to the top without blowing out. Last year I lost almost 1 gal to blow off. I read in a MBAA paper on barrel aging that .5% ABV increase was nominal.

 

[Komodo]

Two things off the top of my head after brewing a 15% RIS very similar to Bourbon County:
1. Gauging how much bourbon aroma/flavor you will get from the oak is extremely difficult. You can age in a used barrel, you can add oak into the fermenter/aging vessel that have been previously used to age distilled spirit, or you can add bourbon. I've done the last two. For aging spirit, you typically use either charred or toasted oak, mine were about 1" square and 6" long. I highly recommend toasted over charred. Toasted is sweeter, has more chocolate and vanillins vs charred which is more spicy. Adding a small amount of bourbon (I used Makers) is probably the most repeatable, easiest to manage, and pretty much has the same end effect.

2. Anytime you get up to 10%+ (arguably maybe 8%+), the alcohol can actually start adding bitterness in addition to the hops. Of course how it is perceived can depend on a myriad of variables, but it's something else to think about.

 

[tracer bullet]

I'm a fan of Imperial Stouts and have been making them a while (not claiming to be an expert though). I've taken to adding a tiny splash of actual bourbon when I want that flavor. You can use a pipette too if you want more control. Then if I change my mind on which bourbon I liek in it, or want a glass without it altogether, it's super easy to do.

I wont' say don't age it in a barrel, but I will say consider skipping that work and adding a splash of the real stuff. Might not be able to tell the difference.