Even the best efforts to remove oxygen with co2 will leave some oxygen behind. The point is not to get to perfection, which is impossible, the point is to get as low as possible. Without a DO meter there is really no way to know how much ingress occurs, but from my reading and research it’s not very hard to hit above 100ppb. Most breweries that look into their handling of beer are surprised to see +100-200ppb of oxygen in packaged beer; almost all breweries struggle with this and it has a huge impact on the quality of beer. Most homebrewers can’t come close to these numbers, but it begs the question; Why tempt fate? Leave well enough alone and enjoy your unfiltered beer. Plus it’s easier.
I suppose one could attempt to measure ppb of O2 and compare bottled CO2 from the tank (low, but some O2) versus using the natural CO2 from fermentation to push out the sanitizer or O2 in the corny. Further, if done properly and timely, spunding reliably takes care of most (if not all) of the O2 in the receiving keg. It all depends on how far you want to go to minimize O2 ingress.
There’s a difference between hot side and post fermentation oxygen, though. Even if HSA is a myth, I wouldn’t want to subject any beer to a lot of O2 at kegging
.
Your assuming perfection in purging. It isn’t perfect, you have mere mortals involved. Even a small amount of oxygen can produce 50 part s per billion. If Weinhenstephan and Sierra Nevada has trouble with it, I’ll have even a bigger problem with it.
If beverage grade CO2 is 99.9% pure is it possible that one could oxidize their beer just by force carbonating it or at least neutralize any antioxidants naturally present prior to carbonating?
Time to quit brewing. It has become clear that we cannot prevent oxygen in our beer. It is simply impossible.
Oh well, I give up.
Might have to find another hobby.
I’m not sure where this went off the rails, but I think good points have been made that are being lost.
Filtering can be a PITA. If you don’t mind doing it, go ahead and continue doing it. Will you get different results than fining/lagering? Yes, likely. Some people like those results, some don’t.
Avoiding cold side oxygen is always good. You’re never going to be perfect, but try for the best you can. Is it harder to purge a filter membrane than an empty keg? In my opinion, yes, just like it’s harder to clean a plate chiller than a counterflow chiller. But if you like the results, go for it.
Although CO2 purity has been mentioned, it’s important to note that force carbonating is much more likely to oxidize your beer than purging/serving with bottled CO2 because of Henry’s law and the partial pressure of gasses. Bryan had posted these articles from Hach a while ago on his blog, and I thought they were very illuminating:
The second article I find fascinating. I’m going to assume that the way most homebrewers carbonate would be considered “injection” vs “sparging” as referred to in the article. Sparging would require venting of the headspace during carbonation through a stone to scrub the oxygen?
For many years I noticed a rapid change in the hop character of my beers shortly after kegging. I’ve since moved to spunding everything I keg and I feel that the improvement in freshness and stability of subtle hop and malt flavors/aromas is undeniable. My previous method of force carbonating was top pressure, set and forget, thus allowing any oxygen in the bottled CO2 to dissolve into the beer via head pressure and time?
I find this article interesting. Especially the part about TPO oxygen variance with the mobile canner: