Does Bottle Conditioning affect ABV?

Discussion in 'Beer Talk' started by Hop-Droppen-Roll, Jan 12, 2014.

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  1. Hop-Droppen-Roll

    Hop-Droppen-Roll Initiate (0) Nov 5, 2013 Minnesota

    I would imagine that a bottle of beer with yeast still doing its thing inside would develop a higher ABV over time, but I've never seen any indication of variability where ABVs are listed...
  2. reverseapachemaster

    reverseapachemaster Initiate (182) Sep 21, 2012 Texas

    Not in a meaningful amount. The amount of sugar necessary to create fermentation is very low. Off the top of my head I seem to recall natural carbonation adds like 0.05% ABV.
  3. Hop-Droppen-Roll

    Hop-Droppen-Roll Initiate (0) Nov 5, 2013 Minnesota

    But over what sort of timeframe? I have to imagine that there's some notable - if not noticeable - difference in abv dependent on how many years a beer is left to sit, especially in something like a heavy barley wine or some imperial stouts...
  4. FarmerTed

    FarmerTed Aspirant (214) May 31, 2011 Colorado

    It depends on the concentration of the priming sugar that you add to the beer. If you dissolve the sugar in 5 gallons of water and add it to 5 gallons of beer, obviously, you'll cut the ABV by almost half. If you just add the sugar directly to the beer without dissolving it in anything, then the ABV will go up a bit (probably in the 0.1-0.2% range, as a guess off the top of my head).
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  5. ChuckHardslab

    ChuckHardslab Disciple (353) Jan 25, 2012 Texas

    Keep in mind the yeast has a finite attenuation capability. At some point it will no longer metabolize sugars left in the beer. If it didn't work that way, many beers would be thin bitter alcoholic water.
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  6. FATC1TY

    FATC1TY Initiate (0) Feb 12, 2012 Georgia

    It doesn't get more alcoholic if thats your question. There's only enough sugar added for the yeast to carb the beer in the bottle. Once the sugar is done, it's done and the yeast goes dormant. It doesn't get cranked up again to do much in the way of alcohol production.
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  7. NHcraftbeer

    NHcraftbeer Initiate (22) Mar 15, 2011 New Hampshire

    if there was a significant amount of fermentation going on the bottle would explode
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  8. reverseapachemaster

    reverseapachemaster Initiate (182) Sep 21, 2012 Texas

    Brewing yeast--saccharomyces--cannot consume all sugars in beer and cannot always ferment a beer until all sugars are depleted. Every strain has certain kinds of sugars it can ferment and an attenuation limit where it will stop fermenting sugar after so much has been consumed.

    The bottle carbonation process is a controlled fermentation of simple sugars. Additional sugar is added to the beer for that purpose. The yeast consume the priming sugar and then stop fermenting. It only takes days for the priming sugar to be consumed (in most cases) and then a few more days for the extra CO2 to absorb into the beer. Beyond the priming sugar introduced for carbonation there should not be additional fermentation in the bottle. Further conditioning should only be the yeast continuing to clean up fermentation byproducts and various non-fermentation reactions between the contents of the beer and any oxygen picked up in packaging.

    Some strains, and I'm thinking saison strains here, are notorious for finding something to eat after packaging due to various reasons and there is unintended additional fermentation in the bottle. That often happens because the yeast were not given proper treatment to finish fermentation before the packaging process began or the beer was packaged too early (or both). Any beer with brett that is not completely dried out will continue to ferment in the bottle because brett eats almost anything and it will produce CO2 by fermenting residual sugars and starches. Other food sources can be fermented but do not always produce CO2 as a byproduct.
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  9. Roguer

    Roguer Poo-Bah (6,506) Mar 25, 2013 Connecticut
    Moderator Society Trader

    I've wondered about this. I always assumed it might affect the ABV over time, but generally only in a minor amount. Especially since a lot of the beers we age are already high ABV; it probably doesn't make much of a difference at all.

    That said, I've seen "variable" ABV listings on beers before (e.g. 9.5 - 11%), and wondered where that comes from. Batch variation?
  10. MarioM

    MarioM Initiate (0) Sep 13, 2009 California

    When bottling my home brew, especially highly carbonated saisons, the abv goes up about .2 - .4 % abv. But once its finished bottle conditioning, further aging won't cause a rise in abv if all the sugars have been converted.
  11. MostlyNorwegian

    MostlyNorwegian Initiate (0) Feb 5, 2013 Illinois

    Umm. Bottle bombs.
  12. ChuckHardslab

    ChuckHardslab Disciple (353) Jan 25, 2012 Texas

    Maybe, consistency between batches is one of those things that's tough to master. It's dependent on many variables. That's one of the things you gotta give to the macros, they turn out very consistent brews. It may not be all that good, but it is consistent.
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  13. doppletheGOAT

    doppletheGOAT Initiate (0) Nov 27, 2012 Texas

    I don't think I've seen a stout that was bottle conditioned. Do they actually exist?
  14. vacax

    vacax Initiate (0) Jun 3, 2008 California

    On the other hand, their consistent ABV is done by the amount of water they add to the beer, isn't it? So not really terribly impressive. I could do the same thing if I had all the fancy equipment to determine alcohol content. I'd say what is more impressive is consistent fermentation characteristics, or their yeast handling.
  15. Homebrew42

    Homebrew42 Initiate (0) Dec 20, 2006 New York

    The bottle conditioning process doesn't continue on for years, the yeast consume the small amount of sugar thats added to the bottle for priming over the course of a few weeks and then the process stops. If it continued on indefinitely not only would the beer become more alcoholic, but the bottle would also explode.
  16. Homebrew42

    Homebrew42 Initiate (0) Dec 20, 2006 New York

    Yes, there are plenty of bottle conditioned stouts.
  17. doppletheGOAT

    doppletheGOAT Initiate (0) Nov 27, 2012 Texas

    such as?
  18. life_is_beautiful

    life_is_beautiful Initiate (0) Dec 19, 2013 Pennsylvania

    Pretty sure that assumption is the best answer
  19. jesskidden

    jesskidden Poo-Bah (2,361) Aug 10, 2005 New Jersey
    Society Trader

    In the US, under TTB regulations, such labeling would be prohibited:

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  20. cavedave

    cavedave Poo-Bah (3,050) Mar 12, 2009 New York
    Society Trader

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  21. Dupage25

    Dupage25 Initiate (0) Jul 4, 2013 Antarctica

    Sugar is like food for yeast. There is a finite amount of sugar in beer. Moreover, in the same way that not all edible substances can be processed by our stomach, brewers yeast cannot metabolize all forms of sugar. Once the fermentable sugar in the beer and any sugar added at bottling are eaten up, that's pretty much it. And most of a beer's sugars are fermented well before bottling. Any alcohol created during bottle-conditioning will thus be very very minimal, and aging it beyond the length of time necessary for bottle-conditioning will have no effect on abv.

    Wild yeast (brettanomyces) is a little different, but beers with brett are usually fairly dry by the time they are bottled anyway, with not much more to ferment. If they weren't, as others have indicated, there would be a lot more exploding wild ales and lambics out there.
  22. SFACRKnight

    SFACRKnight Poo-Bah (1,949) Jan 20, 2012 Colorado
    Society Trader

    Don't listesn to these guys, you can stash a couple SNPA in your cellar and it will turn into bigfoot.
    True story.
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  23. ERRL710

    ERRL710 Initiate (0) May 6, 2013 Illinois

    Brooklyn Black Ops
  24. 77black_ships

    77black_ships Initiate (0) Dec 4, 2012 Belgium

    Black Albert comes immediately to mind as one of countless examples.
  25. hopfenunmaltz

    hopfenunmaltz Poo-Bah (1,869) Jun 8, 2005 Michigan

    Bells makes many.
  26. SierraTerence

    SierraTerence Initiate (173) Mar 14, 2007 California

    Sierra Nevada Stout

    If I remember right, Sierra Nevada Pale, Porter, Stout, Celebration & Bigfoot climb 0.2% ABV during bottle conditioning. Roughly, 0.65 v/v of CO2.
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  27. Hop-Droppen-Roll

    Hop-Droppen-Roll Initiate (0) Nov 5, 2013 Minnesota

    Ok, I feel my question has been thoroughly answered - but now I'm wondering what the point is... why bottle condition? Additional carb? Isn't there sufficient carb at bottling? (obviously not a homebrewer... yet.)
  28. Dupage25

    Dupage25 Initiate (0) Jul 4, 2013 Antarctica

    I'm not a homebrewer either (yet) but I'll give it a shot.

    There is not always enough carb at bottling. Some beers are actually basically flat at bottling; I think Sierra has said that's the case with Bigfoot, for example. For beers which have already been barrel-aged, I think it's quite likely all the carb is gone. The only other option for most beer would be to "force carb" (inject it with CO2) but that has a reputation for not producing fine enough bubbles and also (I think) for speeding up the degradation process.

    I believe most beer in the world (both by volume and by number of brands) is force carbed, as it's quicker and usually cheaper. This includes craft beer.

    There's at least two ways of "bottle conditioning," one of which doesn't really involve bottles. You can add the sugar and yeast in bulk when it's still in the fermentation tank right before bottling, or you can individually add sugar and yeast to each bottle. In the production of sparkling wine, these two methods are known as the Charmat method (bulk conditioning) and the Champagne method/traditional method (individual bottle conditioning).

    The German process of krausening beer is an all-malt way of bottle's functionally the same thing as bulk conditioning. They add unfermented malt to the beer near the time of bottling; the unfermented malt still has lots of sugars (obviously).

    Lastly, all of these processes can be done for canned beer as well. Brewers may choose to use less sugar/krausened malt to lower the risk of the can exploding, as cans are less oxygen-permeable than bottles (meaning there's a greater chance that even a small excess of CO2 will rupture the can). On the other hand, cans are more durable than bottles, so I don't know if that cancels out the risk of overcarbonating....
    #28 Dupage25, Jan 13, 2014
    Last edited: Jan 13, 2014
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  29. Hop-Droppen-Roll

    Hop-Droppen-Roll Initiate (0) Nov 5, 2013 Minnesota

    Great answer, thanks! Krausening is a little confusing to me - it's basically bottle conditioning without yeast, right? What's there to react with the malt to cause carb?
  30. mushrooms

    mushrooms Initiate (0) Dec 24, 2013 Uzbekistan

    Living yeast still in the beer - this works better if the beer is unfiltered, of course. I have never added yeast at bottling to any of my homebrews to condition - they've all been medium-ish ABV (4.5-7.0) and there's been plenty of yeast left to eat the bottling sugar I add, even after cold crashing. Obviously if you're talking about a huge, high ABV beer, you may need a different strain to bottle condition. I believe I've read on the homebrew forums that there will likely even be enough yeast left to bottle condition after filtering, if one goes that route.
  31. jesskidden

    jesskidden Poo-Bah (2,361) Aug 10, 2005 New Jersey
    Society Trader

    While kraeusening originated in Germany, it was adopted by the US lager brewers (almost all of German heritage, of course) and was and still is a common method to carbonate US lagers, even as so-called force carbonation eventually replaced it for many breweries. (Notable existing example include AB's Budweiser and Michelob, NAB's Genesee, BBC's Samuel Adams Boston Lager, Miller-brewed Pabst's Heileman Old Style, etc). It has nothing to do with whether a beer is all-malt or adjunct-brewed.

    To kraeusen, a brewer adds unfermented wort (not "malt"), typically about 15-20% of the volume of the fermented beer, creating a secondary fermentation, in a closed tank so that the newly created CO2 "naturally" carbonates the beer. At Anheuser-Busch (and, today, at most other breweries using it for their beers) the kraeusening stage is done during the lagering period in the lagering tanks.
    #31 jesskidden, Jan 13, 2014
    Last edited: Jan 13, 2014
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  32. sjverla

    sjverla Disciple (397) Dec 1, 2008 Massachusetts

    Throughout the process of fermenting it's generally the goal to remove much of the CO2 that is produced. The pressure that builds up within the fermenting vessel is too great and would be destructive.* When beer is ready to be packaged it's nearly flat since the vast majority of CO2 created has been released. The alternative to bottle conditioning is force carbonating. That's when beer is subjected to CO2 under pressure such that the CO2 dissolves into solution with the beer. This can be done either in kegs or in a bright beer tank.

    *I was on a brewery tour this weekend where they had 1.5" ID blowoff tubes coming of 20bbl fermenters in 5 gallon buckets of water/sanitizer. The off-gassing from active fermentation was so strong the buckets were bubbling over. Lots of CO2 being released.
  33. Hop-Droppen-Roll

    Hop-Droppen-Roll Initiate (0) Nov 5, 2013 Minnesota

    AB likes to brag that Budweiser is Krausened - so you're saying that they krausen early and force carb later?
  34. Hop-Droppen-Roll

    Hop-Droppen-Roll Initiate (0) Nov 5, 2013 Minnesota

    So do homebrewers nearly always bottle condition? Or can force carbing be done on the homebrew level?
  35. jesskidden

    jesskidden Poo-Bah (2,361) Aug 10, 2005 New Jersey
    Society Trader

    No, they carbonate those beers by kraeusening. Here's Stone brewer Mitch Steele's explanation of the process from when he was an Anheuser Busch brewer:
  36. PapaGoose03

    PapaGoose03 Poo-Bah (3,290) May 30, 2005 Michigan

    I don't think that statement is fully correct. I believe that there are breweries that have a proprietary yeast that they filter from the beer, and then a different yeast is added back in for the bottle conditioning process. Possibly there are some filtration equipment/methods that are not good enough to remove the yeast, but I'll bet if it is a yeast that the brewer wants to protect from distribution that they'll have the best filtering equipment available.
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  37. PapaGoose03

    PapaGoose03 Poo-Bah (3,290) May 30, 2005 Michigan

    To my knowledge force-carbonation cannot be done by the homebrewer for bottling. Kegging, yes, but not bottling.
  38. PapaGoose03

    PapaGoose03 Poo-Bah (3,290) May 30, 2005 Michigan

    One other point to add to this conversation is that there are more beers that are bottle conditioned that you'd ever guess. I recall a thread in this forum which stated that over 50% of beers are bottle conditioned, it's just that not all labels will reflect that info.
  39. BillManley

    BillManley Aspirant (232) Jul 2, 2008 Minnesota

    True that. 0.2% ABV. In other words, Pale Ale is bottled at 5.4% ABV and once the sugar is depleted by the fresh yeast, the ABV rises to 5.6% and stays put. The beer is well-carbonated and slightly more alcoholic.

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  40. kdb150

    kdb150 Devotee (448) Mar 8, 2012 Pennsylvania

    All one needs to force carb at home is a CO2 tank and a keg to hold pressure up to ~30 psi. You crank up the pressure, agitate the keg, wait a while, and then crank the pressure down to serving pressure of around 10 psi.

    If desired this beer can be bottled from the keg, but a homebrewer probably won't be able to do this without oxidizing the beer, so it's not recommended for long-term bottle storage.
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