Co2 purity

[aeviaanah]

How important is the purity of co2 in brewing? I have one supplier that uses a Zahm Nagel to check purity and another that does not. The supplier that does wants 80/cylinder refill and the one that doesn't is around 50/cylinder. Both claim this is food grade co2.

 

[Jayjay1976]

Of all the things that don't matter, this don't matter the most...er, the least.

RDWHAHB.

 

[day_trippr]

"Checking" is nice but doesn't mean much more than "checking".
While there are grades of purity expressed I'm not sure there's that much stratification in actual practice. Ie, the predominance of popular opinion is locales share common high-purity sourcing for CO2 regardless of purported grade (short of exotic laboratory needs)...

Cheers!

 

[Bilsch]

Ie, the predominance of popular opinion is locales share common high-purity sourcing for CO2 regardless of purported grade (short of exotic laboratory needs)...

Unlike most compressed gasses which are made from air distillation where it all starts off as high purtiy, CO2 is a waste product or essentially a trash gas. It comes from several sources which are quite variable in the impurities they contain. It really depends on where you are in the country on what grades you end up with. For instance If you live in the midwest chances are very good your gas supplier only maintains one source for everything, short of laser or instrument grade, because they are close to the source of the highest purity supply, namely a biproduct from fuel ethanol manufacture. If you live in the south east or southwest, a lot of their supplies come from natural gas processes and it is very likely your gas supplier maintains several grades of CO2 because he can economically obtain lower grades at a better price then shipping from far away alcohol plants. The list of impurities contained in lower grades of carbon dioxide is as long as your arm, most of which is stuff you dont want in your beer.

The moral of the story is don't assume that the cheap stuff you are buying is actually a higher grade because it's all up to the to the market and the whims of your gas supplier so you never know.

 

[Brooothru]

The moral of the story is don't assume that the cheap stuff you are buying is actually a higher grade because it's all up to the to the market and the whims of your gas supplier so you never know.

All the more reason to use fermenter discharge gas for purging kegs, and spunding to carbonate. Sadly, I still have to use bottle gas to help push closed transfers and dispense from the kegerator. At least I can delude myself into believing that I'm being at least a little bit "green" and not venting greenhouse gas needlessly into the atmosphere.

Intestinal gas, however, is a completely different matter!

 

[Qhrumphf]

I measured a CO2 canister (50lb) this week through an oxygen meter straigh out of the tank (so minimal though non-zero chance for ingress through the small bit of tubing between valve and meter) at 40ppb oxygen. It's well within the tolerance for beverage grade CO2. It's also plenty to oxidize a beer.

 

[Vale71]

It's also plenty to oxidize a beer.

You're kidding, right?

 

[Qhrumphf]

You're kidding, right?

Difference style dependent, but no I'm entirely serious. With something like a NEIPA it makes a huge difference in the shelf life.

 

[Jayjay1976]

I measured a CO2 canister (50lb) this week through an oxygen meter straigh out of the tank (so minimal though non-zero chance for ingress through the small bit of tubing between valve and meter) at 40ppb oxygen. It's well within the tolerance for beverage grade CO2. It's also plenty to oxidize a beer.

You sure have a weird idea of fun.

 

[Qhrumphf]

When 50ppb DO is enough to sound the alarms commercially and you're getting 80% of that from your CO2 supply alone that's too high (the bulk supply I have at work is 5-8ppb, and we can hit <50ppb TPO from grain to package to glass). If you're spunding and only using it to push, not the end of the world. If you're using it to purge or carb, may not be an issue for something dark, malty, and low-hop. But for something light and aggressively hoppy like NEIPA, it means weeks instead of months shelf life before serious drops in character.

 

[Qhrumphf]

You sure have a weird idea of fun.

I don't have fun.

 

[aeviaanah]

When 50ppb DO is enough to sound the alarms commercially and you're getting 80% of that from your CO2 supply alone that's too high (the bulk supply I have at work is 5-8ppb, and we can hit <50ppb TPO from grain to package to glass). If you're spunding and only using it to push, not the end of the world. If you're using it to purge or carb, may not be an issue for something dark, malty, and low-hop. But for something light and aggressively hoppy like NEIPA, it means weeks instead of months shelf life before serious drops in character.

Nice job on getting sub 50ppb TPO. Where are you guys located?

 

[Qhrumphf]

You know just the other day I dropped whatever wage-earning nonsense I was up to and purchased a 50 lbs cylinder of nonsense garbage gas from my local "gas dealer" and just for my own edification I spent the day running it through my gas chromatograph in my basement and discovered it contained like 92 parts per jillion of parcheesi burps.

Edit: just stayin' rude, rebel and sharp...

If you like what you make keep on keeping on. Not my business or problem.

Just saying I've seen major differences between beers minimally run or not run on CO2 gas cans vs otherwise. Especially excessively hopped ones suffer immensely. Even not aggressively hopped beers the difference between 50ppb and 10ppb is immediately noticeable even before it hits a bottle or can. Kegged beer minimizes it from there on out.

But it, if you're relying on canisters to only push (transer and serve) and not to actually carb purge, no big deal. At that point it's not trying to force it into solution.

Oxidation is cumulative. Every little bit contributes. Unless you're fermenting in the same vessel you're gonna serve from (and there you run into autolysis potential), you're gonna pick up some no matter what. Minimizing the pickup from external sources through things like spunding is key.

 

[Jayjay1976]

If you like what you make keep on keeping on. Not my business or problem.

Just saying I've seen major differences between beers minimally run or not run on CO2 gas cans vs otherwise. Especially excessively hopped ones suffer immensely. Even not aggressively hopped beers the difference between 50ppb and 10ppb is immediately noticeable even before it hits a bottle or can. Kegged beer minimizes it from there on out.

But it, if you're relying on canisters to only push (transer and serve) and not to actually carb purge, no big deal. At that point it's not trying to force it into solution.

Oxidation is cumulative. Every little bit contributes. Unless you're fermenting in the same vessel you're gonna serve from (and there you run into autolysis potential), you're gonna pick up some no matter what. Minimizing the pickup from external sources through things like spunding is key.

You have more patience for me than I really deserve, and I appreciate your thougtful reply. Thank you.

 

[Vale71]

When 50ppb DO is enough to sound the alarms commercially and you're getting 80% of that from your CO2 supply alone that's too high (the bulk supply I have at work is 5-8ppb, and we can hit <50ppb TPO from grain to package to glass). If you're spunding and only using it to push, not the end of the world. If you're using it to purge or carb, may not be an issue for something dark, malty, and low-hop. But for something light and aggressively hoppy like NEIPA, it means weeks instead of months shelf life before serious drops in character.

Check your math. Unless your keg only contains CO2 and no beer you're not gettin 80% TPO from 40 ppb O2 in your CO2 (damn, sounds like I'm talking in some weird code...). Headspace in a full keg is about 10% of beer volume so in reality you're getting very little TPO contribution from canned CO2. Now if you're doing gas stripping or quick carbing that's another level entirely...

 

[AMessenger]

With something like a NEIPA it makes a huge difference in the shelf life.

I've seen major differences between beers minimally run or not run on CO2 gas cans vs otherwise. Especially excessively hopped ones suffer immensely

Fear mongering.

Would certainly be interesting to do a proper experiment on this subject to eliminate the strong potential for cognitive bias inherent in a non controlled tasting. How do you know you aren’t just imagining the “huge difference in shelf life“ and “major differences between beers minimally run or not run on CO2 gas cans vs otherwise”?

 

[Qhrumphf]

Check your math. Unless your keg only contains CO2 and no beer you're not gettin 80% TPO from 40 ppb O2 in your CO2 (damn, sounds like I'm talking in some weird code...). Headspace in a full keg is about 10% of beer volume so in reality you're getting very little TPO contribution from canned CO2. Now if you're doing gas stripping or quick carbing that's another level entirely...

Yes. This is the case. Hook up to a carb stone and measure in real time and watch the oxygen level approach the level in the CO2. I don't know my gas laws well enough if it'd reach the exact same number but if from observation if a beer is transferred and picked up 20ppb over the transfer, and then carbed via a carb stone, using a supply with 5ppb oxygen will see the level in the beer drop via gas sparging as incoming CO2 strips out existing oxygen. Same scenario on the other side using a supply with 40ppb. Level starts rising.

 

[Qhrumphf]

Fear mongering.

Would certainly be interesting to do a proper experiment on this subject to eliminate the strong potential for cognitive bias inherent in a non controlled tasting. How do you know you aren’t just imagining the “huge difference in shelf life“ and “major differences between beers minimally run or not run on CO2 gas cans vs otherwise”?

Potential for confirmation bias? Absolutely. Not a controlled experiment and not done blind. But it's from brewing the same thing over and over, and tasting it over and over. As I said, biggest issue with hazy IPAs and faster loss of hop character.

All it means is for freshest character longest, all oxygen matters. It's a source that shouldn't be ignored.

 

[Qhrumphf]

(The cruel irony being that the worst kind of beer for oxidation is also the hardest to spund, without a means to dry hop closed and under pressure)

 

[lagermanted]

I have to weigh in with qhrumphf, there is o2 in co2. Once I confirmed this from my co² supplier years ago, I switched to carbing with sugar. Stopped the major o2 contamination. Most important on beers I keep for months/years.

I still use bottles to purge and and transfer most beers. I am going to change my lager discharge from fermenting to purge kegs.

It did make a minor stability improvements when I started natural carbonation on my kegs, not to the typical cardboard flavors but the, early oxidation notes, light delicate robbing of character that puts the beer on the BOS table.

This is super annal worry issue. Lots of issues to address prior, and as mentioned, drink it quicker to prevent the issue. I like to worry about better beer and keep chasing the perfect pint.

 

[Vale71]

(The cruel irony being that the worst kind of beer for oxidation is also the hardest to spund, without a means to dry hop closed and under pressure)

That can be done with a little inventiveness...

 

[Vale71]

Yes. This is the case. Hook up to a carb stone and measure in real time and watch the oxygen level approach the level in the CO2. I don't know my gas laws well enough if it'd reach the exact same number but if from observation if a beer is transferred and picked up 20ppb over the transfer, and then carbed via a carb stone, using a supply with 5ppb oxygen will see the level in the beer drop via gas sparging as incoming CO2 strips out existing oxygen. Same scenario on the other side using a supply with 40ppb. Level starts rising.

Okay, so we agree that for transfering and serving the regular food grade CO2 is good enough (after all it's good enoug for the industry...) but for more sensitive applications higher grade CO2 is certainly better.

 

[Vale71]

I have to weigh in with qhrumphf, there is o2 in co2. Once I confirmed this from my co² supplier years ago, I switched to carbing with sugar.

How do you add the sugar? If it's in any sort of open container then you're doing a lot more damage to your beer than by force carbing with food grade CO2.

 

[gyfal]

I measured a CO2 canister (50lb) this week through an oxygen meter straigh out of the tank (so minimal though non-zero chance for ingress through the small bit of tubing between valve and meter) at 40ppb oxygen. It's well within the tolerance for beverage grade CO2. It's also plenty to oxidize a beer.

Please, never forget that a ppb is 1 second in 32 years…

 

[bracconiere]

so i was f'in around, 28 grams a mol of o2, 44 grams a mol co2 i believe 50ppb o2 in my co2. i burst carb with 1.2oz's...so that would put it at

0.0000476 grams of o2 in my beer keg? and i still just siphon my beer into the kegs in open air. so for me anyway.

but @Qhrumphf i do like your input! lol

 

[Bilsch]

Isn’t it interesting that even though Qhrumphf has the equipment, data and experience to show the damage being caused by O2 in the CO2, people are still denying and obfuscating. Homebrew dogma is a really hard thing to kill.

 

[Qhrumphf]

Please, never forget that a ppb is 1 second in 32 years…

While that's true, it's also not relevant.

 

[Vale71]

so i was f'in around, 28 grams a mol of o2, 44 grams a mol co2 i believe 50ppb o2 in my co2. i burst carb with 1.2oz's...so that would put it at

0.0000476 grams of o2 in my beer keg? and i still just siphon my beer into the kegs in open air. so for me anyway.

but @Qhrumphf i do like your input! lol

Try again. It's ppb vol/vol not weight/weight or mol/mol.

 

[Brooothru]

lol just heavy weight gases being pushed around? i would have to say jayjay's comment about my lighter and qhrumphs or whatever handle? j/k

edit: i would have to say qhrhump, helped me with something about mashing, and helped get my effec to 92%....

Actually,

If you like what you make keep on keeping on. Not my business or problem.

Just saying I've seen major differences between beers minimally run or not run on CO2 gas cans vs otherwise. Especially excessively hopped ones suffer immensely. Even not aggressively hopped beers the difference between 50ppb and 10ppb is immediately noticeable even before it hits a bottle or can. Kegged beer minimizes it from there on out.

But it, if you're relying on canisters to only push (transer and serve) and not to actually carb purge, no big deal. At that point it's not trying to force it into solution.

Oxidation is cumulative. Every little bit contributes. Unless you're fermenting in the same vessel you're gonna serve from (and there you run into autolysis potential), you're gonna pick up some no matter what. Minimizing the pickup from external sources through things like spunding is key.

I don't have a DO meter to confirm the efficacy of any of the LoDO processes I've started incorporating into my routine. That said, I have noticed marked improvement in my beers, especially in how much longer they seem to stay fresh in the keg.

Right now I use yeast oxygen scavenging for strike water which the LOB website showed reduces DO levels below 10ppb. I treat the mash and late boil with Trifecta. I mash with a full volume/no sparge using a mash cap.

The boil is low intensity, chilled with a stainless steel IC, closed transfer into the fermenter. Oxygenation happens after yeast pitch, and fermentation is spunded to carbonate, and accumulated pressure elimates suckback during cold crash. Any additions in the fermenter are pushed in under pressure with one of Jaybird's yeast brinks. Transfer into a purged serving keg is the first time the beer is touched by 'impure' CO2, and of course is served under pressure with bottled gas.

I have no idea how much oxygen, dissolved or otherwise, is present in my beer but it must be pretty low. From a subjective standpoint I can't detect oxidation since I started using LOB recommended procedures in kegs that have lasted over two months. Funny thing is, none of this has added that much extra effort or complexity to my brewing. The additional investment in equipment has been minimal and incremental with most of the changes being procedural. It's not hard, not expensive, so why is it controversial? I mean, it's not like someone is telling you to wear a damn mask or anything.

Brooo Brother

 

[Ogilthorpe2]

I have to weigh in with qhrumphf, there is o2 in co2. Once I confirmed this from my co² supplier years ago, I switched to carbing with sugar. Stopped the major o2 contamination. Most important on beers I keep for months/years.

I still use bottles to purge and and transfer most beers. I am going to change my lager discharge from fermenting to purge kegs.

It did make a minor stability improvements when I started natural carbonation on my kegs, not to the typical cardboard flavors but the, early oxidation notes, light delicate robbing of character that puts the beer on the BOS table.

This is super annal worry issue. Lots of issues to address prior, and as mentioned, drink it quicker to prevent the issue. I like to worry about better beer and keep chasing the perfect pint.

How do you prime purged kegs with no O2 ingress? Syringe?

 

[lagermanted]

How do you add the sugar? If it's in any sort of open container then you're doing a lot more damage to your beer than by force carbing with food grade CO2.

I add my boiled sugar to my keg, purge and then rack beer into the keg. The sugar solutions are pre-made and canned for stability and convenience.

 

[Ogilthorpe2]

I add my boiled sugar to my keg, purge and then rack beer into the keg. The sugar solutions are pre-made and canned for stability and convenience.

I thought just purging kegs with Co2 under pressure didn't do much except waste CO2? I thought you had to push the sanitizer out of a completely full keg in Order to fully purge? In which case, the only way to get sugar in without opening the keg is with a syringe.

 

[day_trippr]

Those are my perceptions as well. And 300ml syringes are very handy

Cheers!

 

[lagermanted]

I thought just purging kegs with Co2 under pressure didn't do much except waste CO2? I thought you had to push the sanitizer out of a completely full keg in Order to fully purge? In which case, the only way to get sugar in without opening the keg is with a syringe.

I prefer to let my sanitizer drain from the keg. Too many times the nuance of the sanitizer steals the greatness of the beer. If you purge your kegs from the bottom, (out tube) you can get good oxyagen removal. During racking , again fill from the bottom.

A visual check on oxygen is if you splash uncarbonated beer in a CO² environment, and no foam forms, you have a "lower" oxygen atmosphere.

 

[Ogilthorpe2]

I prefer to let my sanitizer drain from the keg. Too many times the nuance of the sanitizer steals the greatness of the beer. If you purge your kegs from the bottom, (out tube) you can get good oxyagen removal. During racking , again fill from the bottom.

A visual check on oxygen is if you splash uncarbonated beer in a CO² environment, and no foam forms, you have a "lower" oxygen atmosphere.

I prefer to let my sanitizer drain from the keg. Too many times the nuance of the sanitizer steals the greatness of the beer. If you purge your kegs from the bottom, (out tube) you can get good oxyagen removal. During racking , again fill from the bottom.

A visual check on oxygen is if you splash uncarbonated beer in a CO² environment, and no foam forms, you have a "lower" oxygen atmosphere.

So much for “don’t fear the foam” eh?

What does purging from the bottom accomplish? The gasses are still mixing inside the keg. It’s not like the CO2 keeps to itself and pushes everything else out.

 

[day_trippr]

[...]Too many times the nuance of the sanitizer steals the greatness of the beer. [...]

Hmm? What are you using for sanitizer? Bleach? Iodophor?

I do the "Star San Purge" thing (unless I can use a fermentation to purge a pair of kegs). There is roughly a teaspoon of sanitizer remaining that the dip tube doesn't reach, before the keg gets filled. I would challenge anyone to detect that...

Cheers!

 

[Qhrumphf]

If you go low and slow to minimize gas mixing you can purge that way. Liquid purging uses less CO2, is faster, and more effective with much less room for error. Especially without a DO meter to verify efficacy of it.

If you're fully blowing out a no rinse sanitizer what in difference is that gonna make?

 

[lagermanted]

So much for “don’t fear the foam” eh?

What does purging from the bottom accomplish? The gasses are still mixing inside the keg. It’s not like the CO2 keeps to itself and pushes everything else out.

From taste tests, I fear any sediment from starsan. My preferred sanitizer but my water causes it to cloud and precipitate. The sediment is very harsh.

Yes oxygen is sticky and will mix in with the co². I purge to 10 psi, vent and repeat 10 times. This significantly reduces the oxygen in the keg. As mentioned, the beer will not foam when agitated by dumping, splashing ect. Naturally I never intend to abuse the beer like that

Proof is in the beer, keep a keg of good beer for a year. Try it,, if it is not tasty you need to work on your oxygen reduction strategy. Purging as i described is part of how I can keep beer beyond normal storage life.

 

[jerrylotto]

i'm going to calculate the molar mass of an atom of oxygen, and co2 then see how many atoms of oxygen 50 ppBILLION an atom compares to co2...but we didn't hear a flow rate for o2 meter....so no idea how many grams co2...i think anyway...

gases (unlike liquids) fractional composition is generally in mole/mole so you don't need any molecular (or atomic) weights to express it. 50 ppb O2 in CO2 is 50 molecules of oxygen per billion of gas.

 

[Vale71]

Except the industry uses vol/vol measurements.