Purging Bottling Vessels - Oxidation

[Nosybear]

A couple of months back I made a Helles. Still trying to get my induction boil dialed in, after primary fermentation I had some leftover beer so I decided to do an experiment. In general, when handling my beers I always purge the receiving vessel with CO2. So I did that with the big carboy, then siphoned the remainder of the beer into a one-gallon glass jug.

I lagered both for the same amount of time. I packaged the one gallon batch into sixteen ounce PET bottles, carbonated with one sugar cube (approx. 3g sugar) each. I packaged the main beer, again, packaging part of the beer as above. Then I let the bottles condition.

Last night I had SWAMBO pour both beers into labeled cups ("A" and "B"). I did not know which beer was in which cup but soon could tell the difference. One was darker in color. The lighter beer was also "brighter" in flavor. In short, it was easy to pick out the beer that had been exposed to oxygen when racked to secondary.

I've argued against LoDo brewing in the past and still will - there's a bit too much magic involved in doing all the steps exactly or the beer will be ruined. But this test tells me that reasonable precautions, avoiding splashing, purging vessels, etc. are worth the time.

 

[J A]

Makes sense to me. I think a lot of homebrewed beer suffers from just a little oxidation along the way and that's why there's just something a little off about it. I like the idea of keeping 02 contact at zero after fermentation is complete, if possible.

 

[Nosybear]

Makes sense to me. I think a lot of homebrewed beer suffers from just a little oxidation along the way and that's why there's just something a little off about it. I like the idea of keeping 02 contact at zero after fermentation is complete, if possible.

It's not possible to completely exclude oxygen - my gripe with the LoDo crowd - but there are things we can do like purging vessels and natural carbonation to scavenge anything that gets in. But tasting the difference was educational, to say the least.

 

[J A]

It's not possible to completely exclude oxygen

Exactly...I try to move finished with CO2 pressure where possible and siphon into fully-purged vessels when I have to use gravity. I've quit worrying about purging bottle when I package from my kegs because the CO2 is actively pushing O2 out as soon as it hits the bottom of the bottle and starts gassing off. By the time I get a cap on it, there's nothing but beer and CO2 in the bottle. That being said, I mostly don't keep bottles around to know that it's particularly effective. Might have to so a comparison next time...purge a couple of bottles and fill a couple without purging and let them sit for a couple of months.

 

[White Haus Brews]

Interesting thanks for sharing. Don't have a way to purge as I don't have a key set up but I've been thinking a lot about limiting o2 recently.

 

[Nosybear]

Interesting thanks for sharing. Don't have a way to purge as I don't have a key set up but I've been thinking a lot about limiting o2 recently.

I have a CO2 tank, a regulator, a hose and a HEPA filter. That's all I need.

 

[J A]

I don't even have a filter on my CO2. I just use a carb-cap on the connector and turn the gas on. If I'm purging a carboy, I'll let it seep in for a few minutes until it's likely that the O2 has been displaced and then check by inserting a fireplace lighter into the vessel. It extinguishes as soon as it goes in even a fraction of an inch. Same with buckets when I occasionally use them. For purging bottles at bottling, I've rigged a bottling wand on a hose and set the CO2 pressure at just low enough to not leak out the end until the plunger is pushed in. Works great.

 

[Nosybear]

I'm using natural conditioning so the yeast cells in the bottle scavenge the oxygen. Great idea on testing the CO2 using the lighter!

 

[Craigerrr]

Thanks for sharing this experiment!

 

[J A]

I'm using natural conditioning so the yeast cells in the bottle scavenge the oxygen.

Yeah, bottle priming is will probably use up O2, but I wonder if there's any discernible difference between bottle conditioned and keg-carbed and bottled. I've got a dark lager in the fermenter and I should have plenty to put up a half dozen bottles for conditioning and do a comparison. Lighter beer would work better because color will probably different if there was any significant oxidation.