Capping on foam

Discussion in 'Homebrewing' started by AceMaster, Feb 5, 2014.

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  1. AceMaster

    AceMaster Initiate (0) Jan 23, 2012 Iowa

    Hi fellow brewers I'm new to Homebrew and was taught that brews should be capped about half inch before the top of the bottle but have heard of folks capping on foam as you would with a growler does this make a difference for the carbing stage bc all of my brews have turned out well and heavily carbonated thanks for any replies
  2. VikeMan

    VikeMan Meyvn (1,353) Jul 12, 2009 Pennsylvania
    Beer Trader

    Not sure what you mean about "does this make a difference for he carbing stage" question. Capping on foam refers to bottling beer that has already been carbonated. When you do this, there will be space between the beer and the top of the bottle, fillerd (temporarily) with foam. The reason for capping on foam is to displace air to keep some of the oxygen out of the bottle.

    You can't really cap on foam with beer that hasn't been carbonated. Well, you could, but the amount of agitation needed to produce the foam in a pre-carbonated beer would introduce more O2 to the beer.
    bgjohnston and Mothergoose03 like this.
  3. OldSock

    OldSock Defender (655) Apr 3, 2005 District of Columbia

    In addition, it isn’t as essential to get the all of the oxygen out of the bottle when you are bottle conditioning. As the yeast eat the priming sugar, they will also scavenge some of the oxygen dissolved in the beer. The less oxygen the better, especially for hoppy beers, but you don’t need to go to extraordinary lengths to have homebrew that tastes great a few months post-bottling.
    bgjohnston and JackHorzempa like this.
  4. AceMaster

    AceMaster Initiate (0) Jan 23, 2012 Iowa

    Thanks for the post I answered my own question after posting bc I realized like u said I can't cap on foam for beer that isn't yet carbed like say for a growler
  5. FarmerTed

    FarmerTed Aspirant (282) May 31, 2011 Colorado

    I cap on foam all the time. I bottle straight out of my fermenter (w/o transferring to a bottling bucket). I just bottle straight out of the spigot on my fermenter, and during the fill I will give a hard pour for 1-2 seconds to generate foam. I'm not always consistent on the fill level (most fills are good enough), but I always have a good layer of foam spilling out of the top of the bottle when I cap. It's hard to do if you use one of the plastic bottle-fillers (not enough agitation to generate foam).
  6. Homebrew42

    Homebrew42 Initiate (0) Dec 20, 2006 New York

    You are oxidizing your beer by bottling this way, this is not a good technique and the quality and shelf life of your beer would be improved by not doing this.
    JrGtr, mikehartigan, FATC1TY and 7 others like this.
  7. ssam

    ssam Disciple (310) Dec 2, 2008 California

    But if you drink the beer fast enough, you'll never taste the oxidation.
  8. Homebrew42

    Homebrew42 Initiate (0) Dec 20, 2006 New York

    Oxidation at this level only takes a few days to become apparent.
    FATC1TY and jbakajust1 like this.
  9. FarmerTed

    FarmerTed Aspirant (282) May 31, 2011 Colorado

    No, I'm not.
  10. mattbk

    mattbk Devotee (471) Dec 12, 2011 New York

    When you "give a hard pour for 1-2 seconds to generate foam" what you are doing is dissolving oxygen into the beer to generate that foam. The more violently you agitate your beer during filling, the more oxygen will be dissolved into the beer. Listen to HB42. He knows what he's doing.
    jbakajust1 likes this.
  11. VikeMan

    VikeMan Meyvn (1,353) Jul 12, 2009 Pennsylvania
    Beer Trader

    Ever wonder why trout live in streams, but generally not in ponds?
    MrOH and wspscott like this.
  12. FarmerTed

    FarmerTed Aspirant (282) May 31, 2011 Colorado

    When you leave 5-10 ml of head-space in your bottle, all you're doing is leaving air in the bottle, which will slowly work its way into the beer, perhaps after the yeast has consumed most of the priming sugar when it can still use oxygen. Please do me a favor and tell me how much O2 is being absorbed by the beer during the hard pour. Are you sure that the CO2 being released isn't just pushing air away from the beer? Do you have a kinetic model that describes how much O2 is absorbed by the beer during the 15 seconds it takes to fill a bottle? I strongly suspect it's less than the air left in the head-space of the bottle after the fill, if you don't cap on foam. Also, this oxygen is in the beer, and will be in contact with the yeast during the early stages of priming, where it will be consumed by the yeast.
  13. mattbk

    mattbk Devotee (471) Dec 12, 2011 New York

    First, do me a favor and tell me how much O2 is kept out of the head space by purposefully foaming it!

    Look: mass transfer is a function of surface area. The more surface area, the more mass transfer.

    When you stir/splash, you are creating more surface area, increasing the rate of O2 transfer to the beer.

    Yes, you liberate CO2, as the mass transfer works in the opposite sense as well. But you also entrain more O2.

    I suspect you are right; carbonation is O2 limiting at first; then sugar limiting. But you don't want any O2 in the beer when you fill, you will begin oxidative reactions that reduce shelf life. That is why every single professional brewery evacuates their bottles with CO2 prior to filling.

    Head space is certainly an issue in homebrew. I suppose I can't say for certain whether you will have improved shelf life by purposefully foaming the beer to push O2 out of head space vs not foaming and having more O2 in the head space. All I can say is I won't bottle homebrewed IPAs anymore.
  14. Homebrew42

    Homebrew42 Initiate (0) Dec 20, 2006 New York

    Please do me a favor and tell me why commercial breweries purge their bottles with CO2 before filling them.

    It's your beer, do as you see fit.
  15. ssam

    ssam Disciple (310) Dec 2, 2008 California

    Maybe in theory, but since FarmerTed's beers don't taste like cardboard (unless they do) in practice its a bit different.
  16. DrewF

    DrewF Initiate (0) Jan 3, 2010 Pennsylvania

    Where did that "credibility" thread go? I have some updates.
    barfdiggs and JrGtr like this.
  17. reverseapachemaster

    reverseapachemaster Aspirant (244) Sep 21, 2012 Texas
    Beer Trader

    If you've tasted a few homebrewer's beers then you know the probability that his beer tastes like cardboard is more likely than not.
    Soneast and FATC1TY like this.
  18. ssam

    ssam Disciple (310) Dec 2, 2008 California

    Drink a beer fresh, and you won't taste oxidization. And use oxy-absorbing caps.
  19. Homebrew42

    Homebrew42 Initiate (0) Dec 20, 2006 New York

    That's bullshit, this is not theory, this is well studied and documented fact, oxygen makes beer go stale very quickly. Have you ever had cask ale that was a day or two past its prime? You don't have to taste outright cardboard to be experiencing oxidation, low levels of oxidation may not yield full blown wet cardboard but will definitely render a beer past it's prime after only a few days. Do you drink wine at all? Ever open a bottle of wine, drink some, and then come back the next day and drink some more? The wine won't taste bad, but it will never the same as it did when you first opened the bottle, and it will go progressively down hill from there. That's the wine becoming stale from low levels of oxidation, and the same thing happens to beer.
  20. ssam

    ssam Disciple (310) Dec 2, 2008 California

    Well yea oxygen makes beer go stale no one is debating this, but you were saying oxygen introduced in the bottle oxidizes the beer in a few days. Do you have some studies or documentation of this? The reason I ask is because the studies I've seen, which admittedly was several years ago, said oxidized beer becomes apparent in several weeks, not days. Show me I'm wrong and I'll concede the point.

    If you bottle already oxidized beer then I can see it tasting off immediately, but otherwise drinking a beer fresh usually doesn't give it enough time to taste oxidized.
  21. FATC1TY

    FATC1TY Moderator (1,229) Feb 12, 2012 Georgia
    Subscriber Beer Trader

    I bet your beers suck by doing what you do.

    Bit if sherry and cardboard are you main go to flavors.. Keep on keepin' on, but don't argue the fact that what you do is less than ideal.
  22. FATC1TY

    FATC1TY Moderator (1,229) Feb 12, 2012 Georgia
    Subscriber Beer Trader

    Okay, think about this though. If you saw that it takes several weeks.. then what would you assume.. 2-3 weeks? 3-4 weeks?

    If you bottle prime, which we are talking about, several weeks is what it normally takes for a green beer to prime, and carb, and then you have to chill it to get the co2 into solution better. Your several weeks have taken place before you get to drink them.

    5 gallons of beer might not seem like much to you, to drink within a week or a couple of days, but I figure most reasonable people don't/can't do so. Therefore, I would think that by doing the really crappy job of bottling like FarmerTed does, that the beers would be oxidized.

    Why do breweries co2 flush their bottles? Why to good growler shops, purge the growlers before filling? Why do beer guns come with the ability to purge your bottles with co2 before filling?

    There's a reason.
  23. mattbk

    mattbk Devotee (471) Dec 12, 2011 New York

    This is exactly my point regarding IPAs. Some styles will suffer less when bottling. IPAs, with their very delicate essential oils, will suffer more. In my experience (not everyone's though)...
  24. ssam

    ssam Disciple (310) Dec 2, 2008 California

    Yea I actually thought of this shortly after my post, so I will concede the point. I was just leafing through some brewing textbooks and while I was unable to find evidence confirming or denying what I said, I did find one interesting tidbit: Oxidation happens slower at lower temperatures. This is actually pretty obvious but can be useful lets say if you suspect a batch is oxidized you can refrigerate it immediately after conditioning to lengthen its shelf life (again, obvious)before oxidation takes hold.

    The bottom line is the less oxygen in your final product the better. I agree that FarmerTed's process is adding more oxy than he should, but I don't think it would be very different to the amount normally in headspace. Using oxy-absorbing caps, chilling the beer after conditioning, and drinking while fresh mitigates the risk of off flavors from oxidation.

    But yea I was assuming around 3 weeks. Most of my bottles are carbed in just over 1, and are chilled in hours. That gives me around 1.5-2 weeks before my 3 weeks are up. Plenty of time to knock back 50 bottles with some friends if you wanted to. And definitely longer than a few days.
    #24 ssam, Feb 8, 2014
    Last edited: Feb 8, 2014
  25. billandsuz

    billandsuz Disciple (315) Sep 1, 2004 New York

    ok, this is very simple.
    there are only a few things that are absolute in brewing, and packaging best practice is one of them.

    you want as close to zero dissolved oxygen in your beer after fermentation is complete. no exceptions. this is not debatable.

    if you bottle condition, the yeast may indeed consume some oxygen that may be present, but it is a risk and adding oxygen is just asking for problems. no brewer has ever achieved 0 ppm dissolved oxygen in their bottling line and you are no exception. this is not debatable.

    foam, that is the release of CO2, will absolutely purge oxygen in the headspace, but 1) oxygen in the headspace is not the same as dissolved oxygen introduced via splashing and 2) unless your beer is fully carbed before capping, as it is in a brewery, you are doing it wrong.

    sophisticated packaging lines inject a violent blast of purified water to agitate the beer and generate the foam needed to purge the headspace. Your brewery is anything but sophisticated, and this too is not debatable.

    DO NOT introduce any oxygen after primary fermentation is complete.
    as homebrewers, you and I are not breaking new ground in the art of packaging.

    end of discussion.
    nickfl, wspscott, Homebrew42 and 2 others like this.
  26. VikeMan

    VikeMan Meyvn (1,353) Jul 12, 2009 Pennsylvania
    Beer Trader

    I agree with everything in your post except this.
    bgjohnston, billandsuz and mattbk like this.
  27. JohnSnowNW

    JohnSnowNW Defender (602) Feb 6, 2013 Minnesota
    Beer Trader

    I'll just point this out...rationalizing poor bottling procedure by advocating quick consumption doesn't make the argument any less absurd.

    ...and now I've just given @VikeMan 's last post weight :stuck_out_tongue:
    wspscott and Homebrew42 like this.
  28. OddNotion

    OddNotion Devotee (478) Nov 1, 2009 New Jersey
    Beer Trader

    But... Funnel???
  29. AceMaster

    AceMaster Initiate (0) Jan 23, 2012 Iowa

    I posted this thread off of something I read in the brewing forum I did not intend on it becoming an argument please disregard this forum as I said earlier I answered my own question
  30. mikehartigan

    mikehartigan Disciple (304) Apr 9, 2007 Illinois

    Don't be modest. You've discovered a completely new viral topic!:grimacing: With a 3,000+ year old hobby, that's something that doesn't come along every.
  31. sarcastro

    sarcastro Disciple (335) Sep 20, 2006 Michigan
    Beer Trader

    It's bigger than you now.
  32. MostlyNorwegian

    MostlyNorwegian Zealot (519) Feb 5, 2013 Illinois

    If you find yourself in a situation where you are capping on foam. You are probably not capping at the homebrew level. Or, if you are. It's far more serious than you let on.
    You are also probably a pretty experienced bottler; cos capping on foam is a ride for consistency.
  33. FarmerTed

    FarmerTed Aspirant (282) May 31, 2011 Colorado

    Sorry, but you're wrong as well. It's funny how I never hear back about sherry or cardboard flavors on score sheets, but feel free to believe what you want to believe. There's a lot of ignorance here, that's all I can say (not that that's a big revelation).
  34. FarmerTed

    FarmerTed Aspirant (282) May 31, 2011 Colorado

    Oxygen in the head-space isn't the same as dissolved oxygen? This is what I have to argue against? Really? Please tell me what the difference is between these two forms of oxygen.

    This is from Garrett Oliver in the Oxford Companion (yeah, I know the book is scoffed at, but his discussion on bottle conditioning is relevant):

    "With the rise of craft brewing worldwide, bottle conditioning is on the rise, if only on a relatively small scale. Some larger breweries have taken up partial bottle conditioning of (sic) a belief that the active yeast will remove oxygen from the beer and extend shelf-life, but this is only partially true. You can remove small amounts of dissolved oxygen from beer, but very little from the bottle headspace air, which means that these benefits will only attain to breweries using sophisticated bottling methods and very good packaging equipment."

    You might try calculating the amount of O2 in the headspace of a bottle of homebrew. It's more than you think. And again, tell me how much O2 pickup there is filling a bottle with a small amount of agitation.
  35. JohnSnowNW

    JohnSnowNW Defender (602) Feb 6, 2013 Minnesota
    Beer Trader

    It's already been pointed out several times that capping on foam is a method successfully employed by the beer industry. However, it has also been pointed out that they purge the bottles with Co2 beforehand. Now, are we supposed to assume that the industry, that has an interest in efficiency and cost reduction, is doing so for shits and giggles?

    It's good that you don't notice any oxidation, or that some of your beers haven't been scored lower because of it. But, you shouldn't be giving advice based on anecdotal evidence. If you have some reliable information on the subject, I think we'd be all ears.
  36. JrGtr

    JrGtr Devotee (400) Apr 13, 2006 Massachusetts

    Yes, there is a lot of ignorance on here, but not a lot from FATC1TY. Going through many threads on here, he's one of the more knowledgeable folks here.
  37. nickfl

    nickfl Poo-Bah (3,451) Mar 7, 2006 Florida
    Beer Trader

    This reminds me of the threads where people argue that their beer tastes "fine" without ever using a starter and therefore, starters are a waste of time for all beers ever... end of discussion no matter what anyone says!

    For the benefit of any new brewers reading this thread: Homebrew42 and Vikeman are experienced and knowledgeable brewers, this other dude is flat out wrong.
  38. Soneast

    Soneast Crusader (745) May 9, 2008 Wisconsin
    Beer Trader

    So you don't see the difference between oxygen that has been forcibly dissolved into your beer due to agitation, and the slight amount of oxygen exposure that occurs at the surface of the beer in the headspace of the bottle? Personally, I would much prefer the headspace exposure versus actively dissolving oxygen into my beer via forced foaming in an oxygen rich environment.
  39. FarmerTed

    FarmerTed Aspirant (282) May 31, 2011 Colorado

    Why am I wrong? Here, let me run some numbers (not that it will help). How much O2 is in 1 mL of air at 20 C and 1 atmosphere of pressure? The answer is ~0.25 mg of O2. So, if you cap a beer with ~10 mL of air in the headspace, you'll be sealing in 2.5 mg of O2 in the bottle, that is going to be sitting right on top of the beer, and much of which will not be consumed by the yeast during carbonation.

    In "Yeast", there's a table on aerating wort, and according to the table you can get 2.7 ppm of O2 in a 5 gallon bucket of wort by shaking it for 5 min. Let's assume the rate of aeration is the same during bottling, with some agitation (I'll call it 5 seconds, which is an over-estimate). At the same rate, you would end up with ~0.1 ppm of O2 in the beer. They use mgO2/L wort to calculate ppm, so assuming the bottle is ~0.35 L (a 12 oz bottle), you can estimate that there will be 0.25 mg of O2 in the beer at bottling. Maybe I've still got 1 mL of air in the headspace. Then, I'm looking at 0.5 mg of O2 in the bottle at sealing time. By my calculations, it's quite a bit less than bottling the wrong way.
  40. FarmerTed

    FarmerTed Aspirant (282) May 31, 2011 Colorado

    I'd rather have it in the beer, where the yeast can use it to propagate and lower the overall levels of O2 in the beer (try seeing Garrett Oliver's article I linked to above). If you want to 'protect' the O2 by having it in the head-space, go right ahead.
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