Literally all beer post fermentation is oxidized. Mine, yours, AB’s all of it. It’s not a matter of if. It’s how much and when will it matter.
There is no straight answer. There are too many variables. Lager or ale, fermentation schedules, yeast sulfur production, yeast sulfite production, purge methods, carbonation methods, the list goes on.
What I do know from ~1300 batches of beer is that my DO pick up from “purging a keg” (few purge cycles) and carbonating (force) is that I saw 2-6ppm o2 uptake during that process. Sometimes I would go from stage A to B in the mash, sometimes boil, sometimes in the fermenter and sometimes in the keg. It’s wasn’t until I was more rigorous with o2 mitigation that stage A stayed around longer and longer. Most people have honestly never even tasted stage A, I know I didn’t for 800 or so batches. I made good beer, won a metric ton of metals, etc etc. it wasn’t until I started to be more conscious of this all that it all came together.
My “pipeline” (I like that) sounds just like Bama’s, with a keg lasting about two weeks from tapping. I must say I honestly believe I start in “brewery fresh” stage A and the fact I ever detected transition to B got me to adopt a number of cold side measures like closed transfers. So I question the assumption that everything starts life in B; maybe small scale batches avoid thermal stress that might get commercial beer there faster, or something. If I’m not deluding myself, how long to B? Everyone’s process has a different set of synergistic elements, no?
I don’t want this to degrade into people defending themselves. Brewery fresh is less than 150 ppb. It means your purge leaves no oxygen in the recieving keg. It means you pick up no oxygen transferring. It means a pure grade of CO2. If your process encroaches upon or surpasses 150 ppb, which is not difficult, then that is the transition. We know from our write up that force carbing alone gets you there pretty quick. Most people are a bad purge or transfer away from never seeing “Stage A”.
Also remember that if you don’t think the statement I made applies to you, then you are in the minority. Which is a good thing.
This isn’t meant to be an insult. It’s a bit disheartening that people are taking it that way. It’s meant to be a rallying cry for improvement. We don’t get any pleasure out of people thinking they brew s***ty beer and that’s NOT what we are saying. It’s just that there is always room for improvement and we have learned some stuff along the way that we like to share in the hopes of benefiting people.
I used to think that about 8 years ago until I started talking to Co2 companies. Beverage grade Co2 is absolutely what you want. That said I still believe that on the homebrew side, as long as you are keeping your beer cold and taking other measures to minimize o2 pick up during racking/etc it’s not as crucial as some make it out to be. Keeping your beer cold minimizes the effects of DO.
But absolutely if you can get beverage grade Co2 I’m not sure why you would settle for anything less, especially if you are force carbbing.
That means it has not been exposed to toxic substances, not that it is pure. It also includes food processing aids.
You can buy food grade lye for making pretzels. That means it has not been exposed to, or contains, substances such as lead.
So you can get food grade CO2 that has O2. I think beverage grade, or better yet, lab grade would be what we want. Not the paintball stuff that some say has oil in it, not food grade.
I see Airgas has “research grade” which is suppose is what you’d want? I just got 10 lbs from LHBS. The place they get it from specifically supplies it to bars and restaurants for beverage dispense, but now I wonder if it’s really pure, or just nontoxic?
“Food Grade” to me means it can safely be ingested by a human as “food”. I believe that’s what the guy I spoke to meant as well. I would not believe “food grade” would be used in a paint ball gun with extraneous oils in it because I and most people I come into contact with normally don’t use paint balls as “food” or paint ball guns as a “food” related device. I guess that’s just me.
Right, CO2 mixed with oil to lubricator a paintball gun is not food grade.
Food grade doen’t mean that you can ingest it directly. Food grade lye is an example. Pretzels and those nice pretzel buns get that tasty skin from being dipped or sprayed with a lye solution to raise the pH. The high pH accelerates the Maillard reactions when baking - yum.
Many use food grade plastic buckets, that means the plastic does not have fillers or dyes that are toxic.
I believe whoever you buy your CO2 from should have a purity declaration, ignore titles like x grade. If they can’t provide purity, we call that a “clue”. I buy beverage grade, and my supplier defines their beverage grade as 99.999% pure.