Capping on foam

Well, this has been an entertaining read, and yes I think I have something new to say.

What does @FarmerTed think is found in the bubbles of the foam he is capping on? Normally breweries do this because the foam is caused by CO2 bubbles coming out of solution. Here there is minimal CO2 in solution, so the agitation & sloshing is causing the O2 (and N2) to move into & out of the beer. The bubbles are full of O2. When they pop, the newly filled headspace is filled with the leftover gas (O2, not CO2)

But what do I know, I don't have a ph.d. and I don't have friends who have an M.S. in brewing sciences.

 

Why do you think it isn't CO2? I said earlier it may not all be CO2. There's still at least .8 vol of CO2 in the beer at the end of fermentation (according to Beersmith). I do know this: if you don't cap on foam, you are leaving air in the bottle. If you don't believe my earlier calculations, it's easy enough to google the density of Oxygen: 1.331 kg/m3 at 20 celcius (kg/m3 are equiv to mg/mL). At ~20% concentration in air, you have 0.266 mg of Oxygen per mL of air. If you're sealing air into the head-space of the bottle, and not displacing any of it with CO2, then I don't see what the advantage is to be extremely careful about handling the beer during transfers, and limiting O2 pickup during transfers. Even if you fill pretty high on the bottle, and leave ~10 mL of headspace, that is ~2.7 mg of O2 that's sealed in the bottle. Whether it's in the headspace or in the liquid at bottling, over time it's going to end up in the beer.

Even if I am sloppy as hell, and saturate the beer with O2 during filling, the max concentration of O2 will be ~10 ppm @ ~ 10 celcius. So, if I'm sloppy as hell, but have little O2 in my headspace, I'll have ~3.5 mg of O2 in the bottle when I seal it. Really, if that's the case, I doubt there's a big difference between 2.5 mg or so and 3.5 mg (or 6 mg) or so on the aging of the beer.

As far as @JackHorzempa 's contention that bottle conditioning removes 99.9% or so of bottled O2, vs. the Bell brewer's statement that it removes 1/3d of the O2, neither statement comes with any context. The Bell brewer may be talking about going from 15 parts-per-billion to 10 parts-per-billion during conditioning, whereas the other scientist may be talking about going from 10 parts-per-million to 10 parts-per-billion. There is likely a threshold O2 level where the yeast just stops removing Oxygen. I have no idea what it is, but neither of the two assertions excludes the other. Shit, I'm sorry if I'm being too nerdy-phd-scientific.

 

Lots of big numbers based upon a primary assertion that you have no evidence for. Yes, there is residual CO2, but there is also all sorts of residual gases in all fluids as they are naturally soluble to some threshold based upon temperature and partial pressures. When I stir a glass of water I don't see bubbling, why? Because the gases inside and outside the fluid are at equilibrium. When I cap on foam from my keg I get bubbling because the gas is supersaturated for the new temp / pressure combo.

So where does all this magically released CO2 come from? Do you prime beyond your desired volumes of CO2 to account for loss from the 0.8 that are assumed to be in solution (though dropping slowly over time due to diffusion)?

 

Some comments directed at no one specifically:

We always talk about cardboard and sherry but my experience is you'll notice oxidation impacts before these flavors develop; the beer will lose brightness of flavors in more subtle ways. My only experience with cardboard was between the six and twelve month mark of an aging sour with an egregiously faulty airlock. But dull flavors will occur in weeks, if not days.

I like that hopfenmalz alluded to other redox reactions that may participate in staling. I've wondered about this but have seldom heard it discussed. Do ions in water such as nitrate, sulfate, and ferric iron, ions that can serve as electron acceptors to drive oxidation reactions participate in staling? I'm assuming not to a significant degree given how some bomb their IPAs with sulfate, but because I have thought about these guys as oxygen alternatives for bacteria, I wonder about their subbing for oxygen in staling reactions.

In grad school I read a geochemistry paper that emphasized that most geochemical reactions that can happen abiotically are accelerated by about 1000-10000x by the presence of microbes. Remembering this made me wonder if this was true for staling reactions, leading me to conclude that yeast must be bad for beer and no sensible brewer would include it in their process!

 

Whaaaaaat? You learned a fact out of context and are applying it to the chemistry of homebrew? In that case, I beieve it 100%! Be sure to quote yourself dozens of times to make it easy for future googlers.

 

Where does the CO2 come from? It's left in the beer primary fermentation. Just using Beersmith (or any other software, I presume), you can estimate the equilibrium concentration of CO2 at any temperature you want under an atmosphere of pure CO2. I usually finish fermentations out between 65-70 F, and the equilibrium concentration of CO2 in that range is >0.8 volumes. And it's actually quite obvious that there's plenty of residual CO2 in the beer, because when you place a cap over the bottle, foam will continue to roll out of the bottle. That's due to CO2 coming out of solution, not air magically mixing with the beer and then flowing out of the bottle, or Gas 'X' coming out of the beer.

I doubt I lose that much more CO2 going straight from primary to a bottle than other homebrewers lose when they go from the fermenter to a bottling bucket to the bottle. How many threads are there from first-time bottlers complaining that they see 'air' bubblers in their auto-siphon during the first transfer? That's pretty common to see, and it's just due to CO2 bubbling out of solution during the transfer.

I'm sorry if you don't like numbers. I've laid my cards out on the table. I'm waiting for someone who disagrees with me to do the same, but so far all anyone has done is tell me I'm wrong. Show me. Numbers (and some references) that are relevant would be the way to do it.

 

Both could be correct. If the yeast that is left in beer is used, it may go into the aerobic growth phase to reproduce and then go anaerobic and use the sugar. If the beer is dosed with the proper amount of fermenting yeast in the anaerobic phase it would go after the sugar without having to reproduce. If I see Mr. mallet again I will try to remember to ask about this.

 

I just want to join the party... I agree with pweiss you can pick up oxidation notes before it goes to wet cardboard. I honestly haven't eaten much wet cardboard in my life so I have trouble with that description. But I have drunk a lot oxidized beer in my day. I had many a tail gates in college were we try to finish a keg that we tapped the night before and pumped it full of air. I wouldn't drink the day old beer now, but back then I did, and it has made a permanent mark on my senses. Maybe some people just can't taste or detect oxidation or they simply like those flavors. And it most certainly can happen over night, given the right conditions.

There, now I am a permanent part of this thread...

 

Nobody has to show you anything. You are the one proposing a method that is radically different from many, many years of standard bottling practice. If it's an improvement that results in less oxidation, the burden is on you to prove it, with data, not just "numbers" cobbled together from your assumptions. As a PhD chemist, you should know that.

 

Well if his assumptions are wrong you can at least poke holes in them. "You're wrong" is not a very strong counterargument.

 

Several people have. But it's not their burden to counter argue. That's not how science and the acceptance/refutation of theories work. "You're Wrong" could/should be more elegantly stated as "What you are claiming is extraordinary and contradicts current widely accepted understanding. Prove it."

If I claim that there are currently elephants on Mars knitting sweaters (an extraordinary claim that contradicts more than one commonly accepted fact), it's not up to you to disprove the assertion. It's up to me to prove it.

http://rationalwiki.org/wiki/Burden_of_proof

 

Capping on foam is only ok when the beer is already carbonated. Beer is carbonated when it has CO2 dissolved into it. Beer at the time of bottling already has a certain amount of CO2 dissolved into it. You accept all of these premises right? The principles of propostional logic therefore validate FarmerTeds position.

The only thing I think people may find wrong about this is that they would say capping on foam is only ok when the beer is fully carbonated. But may I remind you that fully carbonated is relative. Also the bottle should be purged with CO2.

All this to say, its not as outlandish as you are making it out to be.

You say this goes against what professional brewers have established and take for granted. But all of us do that if we don't purge with CO2 anyway.

DISCLAIMER: I'm inclined to agree with you that this introduces oxygen into the system. I just don't think it is significantly different from normal homebrew bottling practice, and it doesn't guarantee a quickly staling beer just like normal practice doesn't.

EDIT:: Taken from the first paragraph of the burden of proof wiki you posted: "Burden of proof" or in Latin, onus probandi, is the obligation that somebody presenting a new or remarkable idea has to provide evidence to support it. In a scientific context evidence is experimental or empirical data (although in some branches, well thought out mathematics may suffice). Once some evidence has been presented, it is up to the opposing "side" to disprove the evidence presented or explain why it may not be adequate.

FarmerTed provided 'well thought out mathematics' as evidence. Now its up to you to explain why that may not be adequate.

 

Not even close. The 'well thought out mathematics' concept relates to claims that can't be proven with data, like some areas of theoretical physics. That's why it says 'in some branches.' Measurement of dissolved oxygen in beer is not such a branch.

 

Tossing a few numbers around is not proof of any kind and even a non-scientist can count the assumptions in his post. Farmer Ted sounds like he is perfectly happy with his bottling practices, but as a chemist he probably has access to a DO meter and could compare measurements of the O2 in his homebrew, a "traditionally" bottled homebrew, and some naturally carbonated commercial brews. That would be interesting evidence.

 

I actually don't own a DO meter, and the measurements are harder than you would think. If you're actually interested, there's a nice powerpoint on measuring total package oxygen by New Holland Brewery. I think you'll see that it's not a trivial thing to do, and I don't have $4K laying around to blow on the equipment needed to make any meaningful measurements. White Labs will measure the O2 in bottled beer for $46/2 bottles, but I suspect they only want to deal with businesses and not individuals. I'm not shelling out $46 bucks and shipping for this, anyway. Even if I got test data that supported my claims, most of you would just discount it, I suspect.

 

Absolutely not, the lack of data is pretty much the ONLY thing we are taking exception to.

 

You pay me, I'll get you data. I don't work for free, lol.

I'm not sure the White Labs test would work, anyway. It looks like they measure air content (nitrogen and oxygen), but after bottle conditioning much of the O2 will be gone, and the volume of nitrogen will still be there and throw off results. That's how they show doing it in the New Holland presentation (removing CO2, then just measuring the volume of gases left over).

Hach has some relevant blogs on bottle conditioning. I'm afraid there are no numbers, but here are a few quotes on using proper methods to measure O2 in packaged beer:

http://tapintohach.com/2012/05/10/when-to-measure-the-dissolved-oxygen-in-beer/

http://tapintohach.com/2012/06/13/total-package-oxygen-101-what-you-need-to-know-to-calculate-tpo/

http://tapintohach.com/2012/06/18/total-package-oxygen-101-measuring-tpo-in-bottle-conditioned-beer/

Of course, there are no numbers in there, but maybe you could leave a comment and get a reply. My feeling is that it probably makes little to no difference how much O2 is in the bottle at filling. From what the Hach blogger says, the yeast removes it pretty quickly. It all seems to agree with what @JackHorzempa has said as well.

 

I highlight my first remarks, just because I can.

That said, I will say the following about science. In my experience it works like this. Someone comes along with what seems to be a novel (or perhaps seemingly preposterous) claim about something. Perhaps that something is a novel process of how to do something. If the claim is indeed scientific, then the claim comes with reported, supporting data and perhaps some theory supporting the claim. In order to show that such a claim is wrong, it is then up to others to produce data that refutes the original claim. Others may indeed simply propose theories as to why the new claim cannot possibly be correct, but (in practically all cases) these are not scientific refutations of the original claim.

Ok, so FarmerTed has described a process (his unique bottling technique), given us some data (his reported sensory observations and those of HB competition judges), and he has provided some theory as to why his novel process apparently works. It is now up to someone to design and then carry out an experiment to show that FarmerTed is either (1) full of beans or (2) possibly onto something valid. Of course, this someone could indeed be FarmerTed himself, no problem with that.

Personally, I think that there may be something (positive) to FarmerTed's process.

There has been lots of good discussion in this thread regarding oxygen uptake, beer staling, and related topics. But none of this has either refuted nor proven this new claim. Simply shouting about something scientific is not science.

RDWHAHB. Cheers!

 

Look into Vernier's equipment. My school has DO sensors along with the associated peripherals. I am sure that I could get one good data if you showed me your bottling process via video...

That said I don't bottle condition anymore so it would be a hassle.

 

I used to have one of their spectrometers, lol. The problem is that the process of measuring is probably going to introduce too O2 into the system the system to make it worth while. The automated Hach tester has a reproducibility of +/- 5 ppb or +/-10% (whichever is greater), according to their literature. I have a feeling that just trying to pop open a bottle, insert a probe, and then take a reading would be hard to reproduce, and I'm not sure what you'll actually be measuring. I have been thinking about just de-aerating some water, pouring it into a bottle and doing a Winkler-type test just to get an idea of O2 uptake during a sloppy transfer, but even that's a pain in the ass, because I'd have to find reagents and practice the test a few times. It wouldn't be quite the same as pouring something that was partially carbonated, either. What I'll probably end up doing is nothing.