[Steve L]

Hi all. I'm planning an experiment. I like to brew a lot and I brew 1 case at a time. Unfortunately I don't drink it as fast as I'd like to so I sometimes run into a bit of aging oxidation. I bottle from a bucket and use oxy-caps.

I've noticed quite a few differing opinions on purging bottles with CO2 when it comes to bottling from a bucket so I thought i'd try a long storage experiment.  I'm bottling this weekend so I'm going to reserve 3 bottles. The first I'm going to purge the headspace with a gas mix (Private Reserve canister), the second with straight CO2, and no purge on the third. I want to see if I can tell a definitive difference or if it's a colossal waste of time.  Does anyone have any suggestions, additions, subtractions or general ideas?

 

[scottNU]

This sounds like a great experiment.  From a testing perspective, you may want to consider adding some replicates.  Two or three at each condition.  This would allow you to increase your confidence on the impact of purging and it would also allow you to add time as a variable (although you would lessen the replicate benefit to a degree if you checked at two or three points). 

I'd love to hear your results when you finish the experiment.

[kramerog]

Including Private Preserve (mixture of Nitrogen, Argon and CO2) seems to me to be an unnecessary complication.    I can see the benefit of using Private Preserve over CO2 in preserving still wine, but don't see a similar benefit in beer.  To me, it would be better to do more replicates with CO2 and non-purged.

[Steve L]

The idea of using the private reserve for me is somewhat more a matter of convenience and cost. If the purging experiment does show a benefit, I think the delivery method using the PR is simpler than my CO2 purging outfit (Williams brewing purchase) and also the cost for me for the PR is cheaper. It would indeed be of added interest if the gas mix does make a difference, although from a pure standpoint of purging O2, I'm thinking you are right and it won't make a difference.

This sounds like a great experiment.  From a testing perspective, you may want to consider adding some replicates.  Two or three at each condition.  This would allow you to increase your confidence on the impact of purging and it would also allow you to add time as a variable (although you would lessen the replicate benefit to a degree if you checked at two or three points). 

I'd love to hear your results when you finish the experiment.

Excellent idea. good addition to the protocol. Also wondered if I should use a brew that is possibly more prone to oxidative issues, such as an IPA. See how it affects attenuation of hop flavor. If I did 3 bottles of each, I could check them at different intervals

[Steve L]

I have a question, I've never kegged, so I know little about the process. I've been researching info on CO2 and such. Does the source of CO2 make a difference? I've seen "food grade" CO2 and others using other sources such as paint ball canisters. If you use a source that is not "food grade" do you need an inline filter?

[jtoots]

I have a question, I've never kegged, so I know little about the process. I've been researching info on CO2 and such. Does the source of CO2 make a difference? I've seen "food grade" CO2 and others using other sources such as paint ball canisters. If you use a source that is not "food grade" do you need an inline filter?

I've never encountered food grade CO2.  Most folks get their CO2 filled at welding supply shops.

[erockrph]

I have a question, I've never kegged, so I know little about the process. I've been researching info on CO2 and such. Does the source of CO2 make a difference? I've seen "food grade" CO2 and others using other sources such as paint ball canisters. If you use a source that is not "food grade" do you need an inline filter?

Food grade CO2 needs to be at least 99.8% pure. Industrial grade is at least 99% IIRC. The difference is the purity, not contamination. In other words, a food-grade CO2 could be as much as 0.2% oxygen, nitrogen, methane, etc; while an industrial grade could have as much as 1% of these other impurities. You shouldn't need a filter for non-food grade CO2.

[mchrispen]

Could I suggest another series purged with pure O2 if you have it? That would be the 'worst case' scenario, with the obvious expectation.

[erockrph]

Could I suggest another series purged with pure O2 if you have it? That would be the 'worst case' scenario, with the obvious expectation.

I wonder if it's possible to "force carbonate" (oxidate?) with O2. I'd be really curious to see what the result is with that. While I don't doubt that oxidation has detrimental effects on beer "oxidation" seems to be turning into the big bugaboo in homebrewing that "infection" was years ago (i.e., if someone has a beer that just doesn't taste right, the first assumption is that it's caused by oxidation unless there's some other glaring fault). It would be nice to quantify exactly how bad the worst case scenario truly is.

[Steve L]

Could I suggest another series purged with pure O2 if you have it? That would be the 'worst case' scenario, with the obvious expectation.

I wonder if it's possible to "force carbonate" (oxidate?) with O2. I'd be really curious to see what the result is with that. While I don't doubt that oxidation has detrimental effects on beer "oxidation" seems to be turning into the big bugaboo in homebrewing that "infection" was years ago (i.e., if someone has a beer that just doesn't taste right, the first assumption is that it's caused by oxidation unless there's some other glaring fault). It would be nice to quantify exactly how bad the worst case scenario truly is.

I like it. I aerate with pure O2 so I do have the ability. I'm going to add that variable. I feel like this will really put to bed, for me, whether or not carbonation scrubs enough O2 from the headspace. So far it seems like I will have 4 variables; straight CO2, gas mix, Pure O2 and no purge. I figure 4 of each sampled at weekly intervals starting 2 or 3 weeks post carbonation. Sounds like fun!

[BrewArk]

I have a question, I've never kegged, so I know little about the process. I've been researching info on CO2 and such. Does the source of CO2 make a difference? I've seen "food grade" CO2 and others using other sources such as paint ball canisters. If you use a source that is not "food grade" do you need an inline filter?

Some of the smaller disposable CO₂ cannisters for pellet guns etc. have oil in them, those you wouldn't want to use w/food, & should be watchful for.  If you're getting them from your LHBS you should be fine.  If you're getting them from eBay, I'd look for the food grade.  If your using the refillable paintball tank, it is likely you are getting the welding/fire extinguisher gas from the hardware store.