How does barrel aging raise ABV?

[PoorInRain]

How does a beer gain more alcohol by aging? North Coast Brewery's Old Rasputin RIS comes in at 9%. Their bourbon-barrel aged version of the same beer comes in at 11.8%. Sierra Nevada's Ovila Dubbel is 7.5% and the barrel aged version is 8.5%. Did they add something fermentable when they racked to barrels? What gives?

 

[Winters49441]

My guess would be the booze left in the barrel.

 

[zachattack]

There's probably some booze left in the barrel.

edit: Dammit Winters beat me

 

[NervousDad]

I don't think they are allowed to raise the ABV using distilled spirits. (that may be a state law, but I thought it was federal) I think they raise the ABV during the brew to help it age better.

 

[FarmerTed]

I don't think they are allowed to raise the ABV using distilled spirits. (that may be a state law, but I thought it was federal) I think they raise the ABV during the brew to help it age better.

Yeah, I'm pretty sure it's illegal to add more than 0.5% to the ABV of the beer using spirits or any sort of concentrating method; otherwise, it has to be sold as liquor.

The real question is: how do they take something that costs $9-10 per 4 pack, and then make a barrel-aged version that is over 20 bucks for a pint?

 

[user 108580]

The real question is: how do they take something that costs $9-10 per 4 pack, and then make a barrel-aged version that is over 20 bucks for a pint?

All has to do with time. The longer something sits in your brewery taking up space, the more it will cost to justify not making other beer with that space.

 

[Homercidal]

I think some breweries increase the ABV in their brewing process, just to give it a hotter, more boozy feeling, which pairs well with the booze flavor from their barrels. I doubt there is enough booze left in a barrel to increase the ABV more than a very slight amount. If there were, the booze company would have bottled it for profit...

 

[cluckk]

How does a beer gain more alcohol by aging? North Coast Brewery's Old Rasputin RIS comes in at 9%. Their bourbon-barrel aged version of the same beer comes in at 11.8%. Sierra Nevada's Ovila Dubbel is 7.5% and the barrel aged version is 8.5%. Did they add something fermentable when they racked to barrels? What gives?

You see this difference likely for one of two reasons. One, some breweries will increase the gravity of their beers that they age in wood. This gives them a better shelf life and more alcohol for balancing with the character of the wood. Two, if they are using used barrels they most likely contain some brett, which can consume dextrines left unfermented by the sacc. Some brewers will actually make a more full bodied version for aging in wood to give the brett more dextrines to eat. Given enough time the brett can increase the ABV considerably.

 

[PoorInRain]

I think some breweries increase the ABV in their brewing process, just to give it a hotter, more boozy feeling, which pairs well with the booze flavor from their barrels...

If they are increasing the abv, then they are changing the recipe and the beer. Right? I can't just make a bigger barleywine than I normally make that I barrel age and call it the smaller barleywine. It is an entirely different beer.

 

[adiochiro3]

Angels' cut? Evaporation would concentrate things a bit.

However, I noticed that my Wee Heavy went from 1.032 at the time of bulk aging in a secondary carboy in a refrigerator to 1.022 at bottling 5 months later, increasing the ABV by ~1.4%. And -- yes -- I let it come to room temp before measuring. The beer sat in my primary for 5 weeks prior to racking. I assumed that was continued slow fermentation. I doubt much evaporation occurred.

 

[Yooper]

I know next to nothing about barrel aging beer, but in bourbon there is always some loss. They call it the "angel's share". Aging long term means quite a lot of evaporation.

I know that beers aren't aged for lengthy periods in barrels, not like spirits, but is it possible that the evaporation, the angel's share, means the same beer has a higher ABV due to the loss?

 

[PoorInRain]

The brett makes sense and my barkeep and I had thought of that, but the two beers I used as an example in the OP do not contain brett. Are we just not happy with the answer we're getting? I guess I understand that raising the OG while keeping the same recipe is the same beer, just bigger. It just feels like raising the abv would create a whole new beer. Thanks everybody.

 

[PoorInRain]

I hadn't thought of the angel's share. That might shut me up.

 

[billl]

"I know that beers aren't aged for lengthy periods in barrels, not like spirits, but is it possible that the evaporation, the angel's share, means the same beer has a higher ABV due to the loss?"

No. Alcohol evaporates more quickly than water. You would lose proportionally more alcohol and, if anything, your ABV would drop.

The only way ABV would rise during aging would be if there were some yeast still active and creating more alcohol. Wild yeasts or brett would certainly do that.

Generally, it looks like many breweries are just making bigger versions of their beer for aging.

 

[PoorInRain]

Does anybody else feel like making a bigger version of a beer is not the same beer? I.e My APA makes a great IIPA if you boil it long enough?

 

[Yooper]

"I know that beers aren't aged for lengthy periods in barrels, not like spirits, but is it possible that the evaporation, the angel's share, means the same beer has a higher ABV due to the loss?"

No. Alcohol evaporates more quickly than water. You would lose proportionally more alcohol and, if anything, your ABV would drop.

The only way ABV would rise during aging would be if there were some yeast still active and creating more alcohol. Wild yeasts or brett would certainly do that.

Generally, it looks like many breweries are just making bigger versions of their beer for aging.

But that's not so. Water evaporates out of barrels in a lower humidity environment, and reduces the volume. I don't know about beer, but this is true of distilleries and I've seen it myself. That's the "angel's share". In a higher humidity environment, it's about equal water and ethanol, but in a lower humidity environment, it's proportionately more water that is lost.

 

[Arrheinous]

Yeah, there is a mingling of ethanol and water vapors so it is a bit complicated.

Which one diffuses into the barrel faster (and whether from gas or liquid state) should ultimately determine the rate.

You also get co-diffusion where the ratio of ethanol to water will change which one dominates.

IIRC at a rum distillery they said the angel's share cuts into their product yield so at higher ABV it seems like more of a balanced loss of water and ethanol (minimal concentration change but loss) versus possibly losing more water than ethanol (concentrating) at lower ABV.

There's also far more water than ethanol in beer and only one molecule can move through a 'gap' in the barrel at a time. Just from probability you stand a better chance of losing a bit of water than ethanol. Those gaps also have to be bigger for ethanol since it's a bigger molecule.

Ultimately, I'd ask North Coast.

 

[thisisbeer]

But that's not so. Water evaporates out of barrels in a lower humidity environment, and reduces the volume. I don't know about beer, but this is true of distilleries and I've seen it myself. That's the "angel's share". In a higher humidity environment, it's about equal water and ethanol, but in a lower humidity environment, it's proportionately more water that is lost.

This is correct. Humidity is the main factor on what evaporates out of the barrel, water or ethanol. There are a lot of things in barrel aging that are not understood by a home brewer. There are a ton of factors that effect flavor in whiskey that I would assume would have some merit in beer as well, just maybe to a lesser extent. If you are really curious on the subject read this PDF on the science of barrel aging for craft distilleries. They even share stories about 16 year old scotch barrels that are opened and have lost half of the total liquid that was put in the barrel originally.

 

[Homercidal]

Does anybody else feel like making a bigger version of a beer is not the same beer? I.e My APA makes a great IIPA if you boil it long enough?

I kind of agree. You have to taste the higher ABV beer with the understanding that they did change the recipe. And even if the recipe were exactly the same, aging in a barrel is also changing the recipe, so no matter what, it's different.

Keep in mind also, that a brewery can call a beer "barrel aged" and it might not mean that it was actually stored in barrels. It might just be a marketing term, used to denote a flavor profile. They may have aged the beer in stainless take containing some bourbon and some charred oak.

This is actually a pretty interesting topic. I'd never stopped to think about it, but it really might just be the case that some breweries age for a year in barrels and lose some water/alcohol, thereby concentrating some of the flavors.

It sounds like a good question to send to New Holland. They barrel age their Dragon's Milk Stout. I know Founder's also barrel ages their KBS and some other strong beers.

 

[billl]

To get from 9% to 11.8%, you would need to evaporated from 5 to 3.8 gallons (or 24% loss)- even assuming 100% of that was water. Unless they are aging for years, that doesn't seem likely.

Not a distiller by any measure, but Scotland seems to report losing about 2% from barrels per year and claims it is mostly alcohol. Of course, it is pretty humid there and they are using much higher concentrations of alcohol.
http://www.undiscoveredscotland.co.uk/usfeatures/maltwhisky/warehouse.html

 

[thisisbeer]

I assumed we were talking a about commercial whiskey barrels that are 59 gallons which put the percent closer to 19% loss in a year to get to that ABV on that beer. Which does seem high, but I have seen reports of breweries losing an average of 10% to the Angels share. I have also read distilleries average between 2% and 5% loss. The Sierra Nevada beer supports the 10% loss theory. 7.5%-8.5% would be about a 9.8% loss in the barrel. Seeing as 7.5% or even 9% of the original beer is ethanol and over 90% is water you will definitely lose more water under the right conditions. Since it's harder for ethanol to escape the barrel in the first place I'm assuming the high ABV of whiskey could slow down evaporation in general more so than a 9% beer.

But seeing as North Coast brewery is..you know...on the coast...I would say they probably do brew a stronger batch for there aged version. Unless they age it for a couple of years, which I don't think they do. But I think it's completely plausible for the Ovila Dubbel to be just a product of the Angels share. Could be wrong. Just my thoughts.

 

[TrustyOlJohnson]

At the Sams Adams brewery in Boston, you can see markings on the ends of the Utopias barrels in the aging room showing a decrease in gallons in the barrel. I believe that beer comes out approx 29% after 10 years aging?

 

[mooshimanx]

I don't think they are allowed to raise the ABV using distilled spirits. (that may be a state law, but I thought it was federal) I think they raise the ABV during the brew to help it age better.

The liquor still contained in the barrels is leached from the wood into the beer, but it is not considered adulterating the drink in contravention of the law. Wooden barrels that's had whisky in it for 5-20 years doesn't have a lot of wood flavor left, which is why you rarely notice significant woody-flavors in barrel-aged beer unless its aged on unused Oak, the way Oak-Aged Yeti is. But at the same time, the booze and bourbon is readily apparent in the beer.

That isn't to say the recipes aren't different on barrel-aged brews. Breakfast Stout and Kentucky Breakfast Stout are not the same base beer at al..

 

[Xpertskir]

How does a beer gain more alcohol by aging? North Coast Brewery's Old Rasputin RIS comes in at 9%. Their bourbon-barrel aged version of the same beer comes in at 11.8%. Sierra Nevada's Ovila Dubbel is 7.5% and the barrel aged version is 8.5%. Did they add something fermentable when they racked to barrels? What gives?

It's either a bigger beer to begin with and/or the ABV increases through evaporation during the aging process.

There can and is some liquor left in the barrel in liquid and wood absorbed form, but I'm guessing that has a negligible effect. Even if there was a half gallon of 40% liquor there would only be a .3% abv increase.

IMO nothing else mentioned in this thread holds water.

 

[thisisbeer]

I linked a study the talks about losing more water than alcohol to the "angels share". The abilty for the aging liquor to gain ABV caused directly by evaporating liquids is a known fact in barrel aging. That's not really up for debate. The only debate was can it lead to that large of an increase in that amount of time. Also whiskeys are rarely aged at bottle strength. A lot of bourbons are aged at 120 proof and diluted to bottle strength afterwards.

 

[PoorInRain]

I just had the pleasure of drinking at Sierra Nevada's Torpedo Room in Berkeley. They had a Torpedo IPA at 7.2% and a Torpedo IPA that had been aged in bourbon barrels for ten months that came in at 10.3%. The bartender told me, unequivocally, that the base beer was identical and that the residual alcohol leftover in the barrel did raise the ABV by the 3.1%. I expressed doubt, but he maintained the the bourbon left in the barrel at "cask strength" was what raised the ABV.

 

[Gixxer]

I think North Coast has two recipes for the regular Rasputin and the barrel aged. The regular Rasputin has like 70 or 90 (dont remember off the top of my head) IBU's and the Barrel aged has like 38. Its a different recipe. Cause there's a difference in IBU's thats what leads me to believe the recipe is different in that case. However I could completely understand how residual alcohol leftover in a bourbon barrel could add a few points of ABV.

 

[tagz]

I don't buy the evaporation theory or the booze theory. Spirit additions are regulated and there's no way an IPA is going to gain 3% in ten months through evaporation. It's an adjusted recipe.

 

[thisisbeer]

I'm not sure what you don't buy? The evaporation and booze aren't exactly theories. Both can cause ABV to rise. If you put beer in a barrel with 80% bourbon which is normal cask strength you would obviously get more alcohol introduced to the beer. I think people don't realize how much whiskey is left in the oak itself. I know its regulated and they can't add bourbon to the beer but how would they regulate how much whiskey is still trapped in the oak? Also don't forget about Jim Beam Devils Cut. Which is made from the whiskey tapped in the oak barrels after they are emptied. They take the empty barrels and fill them partially with water. Then they proceed to spin the barrel at a high speed to extract whats left in the oak. After there done they blend it with Jim Beam 6 Year Old Bourbon.

Note: JB 6 Year old bourbon is 80 proof while Devils Cut is 90 Proof leading to a 5% increase to ABV. I don't know which bourbon they extract the "Devils Cut" from but the highest proof Bourbon made by Jim Beam is 86 Proof (JB Black). I assume the cask strengh on all of there bourbons is the same either way. But there is no doubt the Devils Cut is the reason for the ABV in the bourbon. Also note the ABV increase is 5% after the Devils Cut is diluted with water in the extraction process and blended with JB 6 Year Old. I'm also not sure what the blending ratio is but I would assume it is substantially more 6YO than Devils Cut seeing as how readily available the Devil Cut is in the stores.

Also try aging a beer on plain white oak compared to oak that has absorbed a bourbon. Huge difference in taste. It's obvious the bourbon is what gives the flavor to these beers so there has to be plenty of bourbon there. Also consider most homebrew recipes have you soaking anywhere from four to six ounces of bourbon on oak chips then adding it all to secondary. If you scaled that up to a 55 gallon barrel that's around half a gallon of bourbon on the higher side. Enough to give you close to a 1.5% increase alone if the guys math above is correct. I know there has to be more than a half gallon of bourbon left in a barrel just speaking from experience. That plus in ten months you will have a percentage loss to evaporation. This could be anywhere from 2%-6%. So I think its perfectly plausible to gain 3% in ten months.

Do I know that's what happened? No I don't. But it can't be overlooked. If you really want to learn about barrel aging I suggest you buy some barrels from deep south barrel company and try aging a few yourself. Jack daniels makes an unaged rye whiskey I have aged a couple of times. And again I'm not saying it's not a different recipe for sure. I just wouldn't write off those two factors so quickly.

 

[tagz]

The evaporation and booze aren't exactly theories. Both can cause ABV to rise.

No need to be condescending. I was clearly referring to the theories posted here regarding the degree of abv increase, not the science of evaporation or absorption.

In any event, it turns out the alcohol is derived from the barrels. Here's a few quotes from articles on california barrel-aged beer regulations:

Some barrel-aged beers can gain as much as two percentage points of alcohol by volume during this time period, far exceeding the half-percent ABV increase that the Board of Equalization agreed upon as the fortification limit before a beverage must be classified — and taxed — as a distilled spirit.

Altimari purchased a half-dozen used Heaven Hill bourbon barrels from Kentucky several years ago. He has released several barrel-aged stouts since, and now, to avoid paying the alcopop tax, Altimari slightly dilutes his barrel-aged beers with weaker ales — a common method among brewers leery of paying the tax.

North Coast Brewing Company’s Old Rasputin Russian Imperial Stout measures 9% ABV in conventional form, but a special bourbon barrel-aged version first produced several years ago has measured up to 11%. When the alcopop tax took effect almost 18 months ago, the Fort Bragg brewery made no objections.
“We just went ahead and paid the distilled spirit tax because we’re good citizens,” says Mark Ruedrich, North Coast’s president and brewmaster. “These beers aren’t a big enough part of our business to make it worth our time to complain.”

 

[thisisbeer]

I wasn't trying to be condescending. If you got that impression then I apologize. Even at the end of my post I admitted I could be wrong. But I do disagree with ending your post in a fact such as. "It is an adjusted recipe" when you had no idea. This is a forum and It's fine to disagree but back up your thoughts or opinions with theories or facts. We are all on this forum to learn and far to often there are people stating wrong information as facts. That is me being a little condescending.

 

[tagz]

I assumed most adults would be able to infer that I was stating my opinion. But, I see that you are from Texas. My bad.

 

[rico567]

But that's not so. Water evaporates out of barrels in a lower humidity environment, and reduces the volume. I don't know about beer, but this is true of distilleries and I've seen it myself. That's the "angel's share". In a higher humidity environment, it's about equal water and ethanol, but in a lower humidity environment, it's proportionately more water that is lost.

This. We took a tour of the Stranahan's Distillery in Denver, and the barrels in the aging room are continuously misted with water. Given Denver's extremely dry environment, it was explained to us that this is required to prevent the angels from getting more than their share.

 

[thisisbeer]

I assumed most adults would be able to infer that I was stating my opinion. But, I see that you are from Texas. My bad.

Wow! Look man I'm sorry you took things so hard. I really do apologize. I had no intention for things to be taken so personal. Hopefully things go differently the next time we speak on here. Until then relax and drink a homebrew and enjoy everything this hobby has to offer.

 

[tagz]

Wow! Look man I'm sorry you took things so hard. I really do apologize. I had no intention for things to be taken so personal. Hopefully things go differently the next time we speak on here. Until then relax and drink a homebrew and enjoy everything this hobby has to offer.