Food grade Co2?

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unakabrew

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I found an older post that touched on this topic but not directly.

How important is it to use food grade Co2 when kegging? I just found a used 20lb Co2 tank from a guy ($70) and was going to take it to the local welding shop and get them to fill it. My wife is concerned about "dirty" Co2 tanks and gas. How big a deal is this?

Thanks

Unakabrew
 
unakabrew said:
I found an older post that touched on this topic but not directly.

How important is it to use food grade Co2 when kegging? I just found a used 20lb Co2 tank from a guy ($70) and was going to take it to the local welding shop and get them to fill it. My wife is concerned about "dirty" Co2 tanks and gas. How big a deal is this?

Thanks

Unakabrew

None ... I've never had a tank filled with "food-grade" CO2 and have never experienced any negative effects. Same with everyone I know that kegs.
 
From what I can tell reading around on this topic there is not really any difference in the gas itself, it has to do with the cylinder. Supposedly in food applications there is the possibility of backflow into the cylinder when it becomes empty and if it's a regular steel welding cylinder this can cause the interior to rust and contaminate it. So some cylinders are glass-coated on the interior for this reason.
 
Thanks, guys. That's pretty much what I have found in my readings, too.

Since sanitation is so critical in the brew process, and since we go to such great lengths to ensure sanitation, I wanted to be sure I wasn't overlooking anything as I begin kegging.

I picked up my Co2 tank at lunch so I hope to keg some Irish (Sorghum) Stout tonight!

Unakbrew
 
Glad someone tossed this out there. I had to switch to a new facility to get my tanks filled. Previous place was a soda/water bottling company that stopped doing walk-ups. I filled up last time from a fireman supply store. I swear that their CO2 is contaminating my beer. 3 kegs now that if I pre-carbed in the holding tank taste wack ( 2 dumpers) which is their CO2 and it tasted fine going into the keg. It's a brand new tank just purchased too. The beer on the kegerator is fine for those beverages I didn't pre-carb (filled by the soda company).

Thought I was nuts and may be but I decided to ask the brewpub owner I know and he says there can be a difference. He's got a masters in geology and used to work at various mining companies out here before getting out of that business. He said they just get the co2 local around here via drilling and contaminants can exist.

Needless to say I'm getting mine filled where he gets his service go forward. Your mileage may vary.
 
All:
There is a HUGE difference in various CO2 QVL's (Quality Verification Levels - there are five).
ISBT (International Society of Beverage Technologists) has CO2 Guidelines for quality - this is what you want. Also CGA G-6.2 QVL I is Beverage Grade CO2 equivalent to ISBT.
"Food Grade" is QVL H. It is technically not Food Grade, it is Food Processing Grade.
Beverage Grade/Quality (ISBT/CGA G-6.2 QVL I) mandates many more impurities be removed that are not even checked in QVL H such as:
Benzene (yes BENZENE), ammonia, phosphine, much lower levels of sulfur and acetaldehyde both of which will affect taste, oil and grease and methanol.
You don't want higher levels of sulfur and acetaldahyde and you sure don't want unchecked benzene levels.
 
Holy old post Batman.

Geez, it is. But if what Mark said is true, I just learned something. I've heard that the welding grade CO2 needs to be pretty pure also, and is food-safe.


By the way Mark, welcome to HomeBrewTalk!
 
All:
There is a HUGE difference in various CO2 QVL's (Quality Verification Levels - there are five).
ISBT (International Society of Beverage Technologists) has CO2 Guidelines for quality - this is what you want. Also CGA G-6.2 QVL I is Beverage Grade CO2 equivalent to ISBT.
"Food Grade" is QVL H. It is technically not Food Grade, it is Food Processing Grade.
Beverage Grade/Quality (ISBT/CGA G-6.2 QVL I) mandates many more impurities be removed that are not even checked in QVL H such as:
Benzene (yes BENZENE), ammonia, phosphine, much lower levels of sulfur and acetaldehyde both of which will affect taste, oil and grease and methanol.
You don't want higher levels of sulfur and acetaldahyde and you sure don't want unchecked benzene levels.

Damn, good post; bumping this for newcomers
 
Here's a test the home consumer can do, the taste test. Take some spring water and bubble the co2 through it for a while then taste the water. If it has a rubbery or any other off taste - bam there you go don't use it if you don't want your beer to taste like that. The taste test rigs usually they have a pin lock keg they put the water in, then bubble/pressurize that with CO2, then draw some out to taste.

Right sometimes the industrial grade products have higher purity requirements than medical or food grade. Sometimes there are other quality tests done that aren't done on industrial grade, such as the benzene mentioned above.

I've also seen a FCC (Food Chemicals Codex) grade CO2. The beverage grade checking for benzene was mainly pushed by Coke and Pepsi some years back, I think that was around the time random samples of beverages in stores were turning up benzene, but it was thought those products contained potassium benzoate as a preservative that was breaking down into benzene.
 
Damn, good post; bumping this for newcomers

No offense, but a quick Google search for the info in that post doesn't pull up anything but reposts of that same material. Plus it comes from someone with a single post... raises all kinds of red flags for me as to the validity of the statement.
 
No offense, but a quick Google search for the info in that post doesn't pull up anything but reposts of that same material. Plus it comes from someone with a single post... raises all kinds of red flags for me as to the validity of the statement.

Hmm, good point.

I did some digging and found a few more threads (all from this forum, which is the reason I joined :ban:)

https://www.homebrewtalk.com/f35/food-grade-c02-260588/
https://www.homebrewtalk.com/f35/food-grade-co2-18805/
https://www.homebrewtalk.com/f35/food-grade-co2-vs-industrial-co2-199270/
https://www.homebrewtalk.com/f35/co2-kegging-322631/
https://www.homebrewtalk.com/f35/there-such-thing-industrial-co2-180925/
https://www.homebrewtalk.com/f35/what-type-co2-do-i-need-220097/

Tons of opinions:

- some say welders/industrial is more pure than food grade because welders get screwed up with impurities
- others say that food grade is more pure and that industrial has an argon gas mix
- still others say that industrial is the same as food grade, that they're the same thing
- minority opinion is that industrial contains machine oil; this is unsubstantiated though and it may be the posters were thinking of paintball CO2, which no one seems to recommend using

Others say an inline filter will take care of any impurities out there, others say the gas doesn't matter, the cleanliness of the tank is what matters

All in all, very confusing :confused:
 
Yeah I read some very conflicting things when I first built up my keezer. To add another thing to the list, I've heard a bunch of people say that their local welding shop and beverage supply stores both use CO2 recovered from a large brewery (ex AB).

Here's what I did, to try and balance practicality with these potential safety issues:
1) I can easily imagine some contamination issues coming from sketchy old steel tanks, so I bought a new aluminum cylinder that I never swap. I also chose a regulator with integrated check valves.
2) As a CO2 supplier I chose a local fire extinguisher shop that's known for filling cylinders for home kegerators (I found out about the shop via a homebrew club's web site, and the guy at the shop told me they fill tons of tanks for homebrewers). I figured if their CO2 was a problem, somebody would have noticed by now.

If you know your tank is clean, but you suspect your CO2 is giving the beer off-flavors, I'd just switch sources. If you're lucky enough to live near a major city, there's probably one or two welding/homebrew/fire extinguisher shops that the majority of homebrewers use, so ask around.
 
Well I have seen the local gas supplier filling beverage/supply and welding supply co2 from the same line, told me that they only have ONE main tank for co2. They're a large chain supplier (coast to coast) so take it for what it's worth I know personally how pure welding gas has to be did a ton of food grade welding where FDA personal wold take a perfectly good weld and make us cut it open to check for contaminates/and inclusions bites when there done you get to weld it closed.
 
- others say that food grade is more pure and that industrial has an argon gas mix
That one I know is incorrect. There are multiple gas mixes used in the welding industry, particularly with regard to CO2, which is likely where the confusion lies.

However, if you ask for CO2, you get CO2. There is no "mix" unless you ask for one, regardless of the application.
 
BTW

I just pickup (exchange) a 5# CO tank from a local brewing supply store and the label from AirGas company state it is food grade CO...
See attach

Also, they charged $25, i recalled only paid around $10 from a local gas supplier to replace an empty tank a while ago..

is $25 a good pricing for exchanging a CO tank?

:confused:

IMG_1029.jpg
 
What about a metallic taste in keyed beer? It's only been in keg "soda keg" for about 2 weeks? Anyone had this before, I'm new to kegging.....
 
There is a difference between captured CO2 and CO2 that everyone else uses. CO2 is carbon dioxide and as such is always just that. Food grade or Industrial, always the same. Captured CO2 is subject to various impurities and off-gassing from the fermentation process, this is the main difference.
 
Were CO2 is sourced is the same were it is stored how it is stored and handeled is not the same.
https://youtu.be/yWJaA27QOkE

Would be much more useful if the video provided actual information about how the storage and handling differ. As it is, it just says they are different. Not very informative.

Brew on :mug:
 
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