The pressure of the CO2 is not what matters - it is how you use it. No transfer will be perfect, so I agree that it is better to wait until the last minute so that any oxygen exposure has less time to do harm.
Agreed. Every minute that the beer sits in the bottle it’s losing comp points. That’s just based on what the LO guys have said about the seal on a bottle compared to beer being stored in a keg. If you want to help that situation you could do the wax coating over the cap to keep as much O2 out as possible.
I’ll tell this story from the LO forum: The experiment was whether O2 got into sealed bottles. The brewer filled six bottles the same way and three of those bottles went into the fridge while the other three bottles went inside a keg that was sealed and pressurized with CO2. All of it was kept cold and X amount of time went by (2 months, 3 months?). At the end the brewer opened a bottle that was stored inside the keg and the beer tasted fresh and the color was as it was on bottling day. The bottles stored in the fridge outside of the keg were not as fresh-tasting and oxidation had darkened the color noticeably. O2 and finished beer are not friends.
+1. I learned this from the LODO guys: Dalton’s law states that the total pressure in a closed system containing a mixture of gases is equal to the sum of the partial pressures of each of the individual gases.
The gas molecules are so far apart from one another that each acts independently. There is presumably very little oxygen in the head space of a bottle of beer. So the oxygen partial pressure is low. The primary partial pressure in the bottle is from CO2.
The amount of oxygen in open air leads to about 3 psi partial pressure of oxygen outside the bottle.
So, the oxygen partial pressure outside the bottle is higher than the oxygen partial pressure in headspace of the bottle. This net decrease in pressure from outside to inside the bottle leads oxygen to want to get into the bottle.
With bottles capped, and stored at 34 degrees, how much O2 will invade the bottle? With the internal pressure being greater than the external pressure, it would seem impossible for anything (O2) to invade the bottle.
Does this happen with commercially bottled beer? I always check for the brew date in order to get the freshest beer possible. But never had any issues with beer that was 3 to 4 months old.
I do not enter comps so my experience is zero but… do comps allow cans? Canning is much better at keeping O2 out of the beer and canning systems have come down in price. I don’t really have a need for “beer to go” very much but if I did I would invest in a canner. Handy people can try to automate the canning process and also attempt to purge the can with CO2 prior to canning, etc. I know some people who bought a canner for $1500, then they came down to about $800 and I think I saw one recently that was $450. Then there is the cost of the cans. I’m not necessarily suggesting it but it would be better than bottles. Even the O2-absorbing caps whiff compared to cans.
I am not a scientist but I can’t tell you how many times I have seen this question asked. It is not impossible for O2 to get into the bottle and it has been proven. Don’t ask me for the scientific explanation but beer will stale in the bottle. Yes, it happens to commercial beer as well despite the brewery’s best effort to reduce it. Cans are better. As a non-scientific person, the best thing I can do is hear the information, digest it, accept it and know that beer that is bottled is subject to O2. I can also thank the people who brought the information to the public.
If entering a comp, I will bottle a couple while transferring the rest to a keg. I add 2.2g table sugar to each bottle and let them carb naturally. For someone who has repeatedly failed with a beer gun, this is a great solution.
Good idea.
My first attempt with the Beer Gun (V2.0) was a disaster.
Fortunately, after reading the owner’s manual, and getting good advice here, my second attempt was executed flawlessly.
Dalton’s law is a physical law, counterintuitive as it may seem. The O2 concentration in air is 21%. 14.7 PSI * .21 = 3 PSI that will force O2 in.
The very best commercial crown caps let 1 ppb in per day, and that is what ABInbev uses. So best case is that after 2 months the level would be 60 ppb. Run targets at some high quality breweries is about 50 ppb packaged. What comes through the cap is additive. 200 ppb is trouble for beer. Oh, our caps are more like 5 ppb/day or worse.
The polymer material and clamping force are some factors in this. Sierra Nevada changed from trust off to pryoff around late 2007 to get longer shelf life. A superior polymer was found, but it needed a higher clamping force to work
As someone who has judged many competitions, more likely than not the oxidation from a well-packaged beer will only matter if the beer is one of the top beers in a flight or at the best of show round. Why? Two reasons- the huge range of quality among entries and the fact that all entries have to be packaged at some point. Brew and submit the best beer you can, package it carefully, and accept what comes. Oxidation coming from outside into a capped bottle is probably one of the least likely variables to affect your score.
I think that for competitions, bottle conditioning and selecting styles for entry that are not as subject to noticeable degradation compared to lighter, pale beers are justifiable considerations. Within a category, that may mean little to no difference, but depending on the category styles’ make up, it could make a difference. Even so, I typically enter the lighter lagers and just package as close in time as I can. Then as to NHC - I simply plan to re-brew. Though, I must say, competitions are not on my radar presently - with the exception of my club’s sponsored event this spring.