Where does the possibility of oxidation come from?

[Polcho]

More specifically, when transferring from fermenter to bottles or kegs, where is the prime source of oxidation from?

My thoughts are just from the end of the tube/bottling device.

The reason I ask is that I have read somewhere that when the top is taken off the fv, O2 will go in and the possibility oxidation can be an issue.

I wonder if this is actually true, since the fermentation causes CO2 to rest on top of the beer, thus sealing it. Wouldn’t it simply follow the beer down when siphoning/opening the tap, as it’s heavier than air?

 

[RichardM]

Splashing when transferring will be primary cause.
Taking the lid off won't make a lot of difference.
As for CO2 forming a protective layer, you need to surch for the post on here explaining how gases mix.

 

[trummy]

This question I have asked - without a real plausible answer. My gut feeling is its a case of not disturbing the head of the beer to create too much turbulence, but even then the Co2 should reseal the top of the beer.
The other day I was thirsty working in the greenhouse, a 2 ltr bottle with only about 3 inch of beer in it was on the bench (I was going to use it for slug traps)- been there weeks. Took the top off, drank it and it was fine.

 

[foxbat]

More specifically, when transferring from fermenter to bottles or kegs, where is the prime source of oxidation from?

Mostly splashing around during the process, then followed by a slower process of exposure once the keg is sealed if it's not purged. Splashing speeds up oxygen exposure and is highly beneficial before fermentation and harmful afterwards.

I wonder if this is actually true, since the fermentation causes CO2 to rest on top of the beer, thus sealing it.

No it doesn't cause any 'resting on top'. The large volume of CO2 produced during fermentation purges the headspace making it a CO2-rich and O2-poor atmosphere.

Gas molecules are never at rest above absolute zero. If they were then we'd all be stone dead as air stratified into CO2, N2 and O2 with CO2 being at the bottom. At room temperature the molecules that make up air are moving around randomly at several hundred metres per second.

 

[MickDundee]

Have you been reading Facebook brewing groups? Some of them are obsessed with not taking the lid off.

The only oxidised batches I’ve ever had were through my own stupidity. Some styles are more prone to oxidation than others as well.

 

[RichardM]

Have you been reading Facebook brewing groups? Some of them are obsessed with not taking the lid off.

The only oxidised batches I’ve ever had were through my own stupidity. Some styles are more prone to oxidation than others as well.

As I said, either in another thread here, or on one of the Facebook groups, in the past some breweries used open fermenters and they never suffered from oxidation.

 

[Polcho]

No, I don't use social media, save from work, and my daughter deals with that side, I never see it. I'm wading through the books I brought, kindly recommended by you guys. I've done a fair bit of larger scale wine making, but beer is a new, and fascinating hobby to me.

I now have the Brewzilla and I'm looking to do my first AG brew next weekend hopefully. Just trying to to become informed enough, not to have to throw it out

 

[The-Engineer-That-Brews]

No, I don't use social media, save from work, and my daughter deals with that side, I never see it. I'm wading through the books I brought, kindly recommended by you guys. I've done a fair bit of larger scale wine making, but beer is a new, and fascinating hobby to me.

I now have the Brewzilla and I'm looking to do my first AG brew next weekend hopefully. Just trying to to become informed enough, not to have to throw it out

I too read everything I could get my hands on before my first AG brew (about this time last year, if I remember correctly) - I was petrified of getting it wrong (and I did, slightly) but the beer was still better than anything else I'd brewed by a country mile. Well WELL worth the effort, and it's easier than you imagine.

What are you planning to brew? Unless you're doing a lager, I wouldn't worry too much about oxidisation if I were you - it's highly unlikely to be a problem. It IS worth chucking half a crushed up Camden tablet into your water before it gets anywhere near the grains though as chlorinated tap water is a devil.

 

[chthon]

Do everything regarding wort gently:

• Gently stir your mash
• If you crush your grain on brewing day, you can get a bit of an advantage by making your grains a bit damp
• Filter gently and make sure the outlet of your filter remains under the wort in your kettle (I use a silicone tube)
• When racking, always position the outlet of your racking tube as deep as possible and keep it under liquid

I still move my mash into a filter bucket, but I don't have any problems with oxidation of wort or beer. My blonde beers stay blonde.

 

[JockyBrewer]

As I said, either in another thread here, or on one of the Facebook groups, in the past some breweries used open fermenters and they never suffered from oxidation.

During fermentation it’s fine, it’s when the krausen has dropped that oxidation can occur.

 

[JockyBrewer]

From my experience with oxidation it’s most common with hoppy pale beers. The freshness of the hops fades and you get a slight caramel flavour appearing.

I’ve found the biggest culprit for this is bottling, when you end up leaving fresh air in the headspace and then sealing it in.

You need some headspace to allow for expansion/contraction of the beer, but I think probably a centimetre is probably enough. Modern crown caps also help reduce the problem by having an oxygen absorbing liner which works for several days once wetted.

The ideal situation though is to get the beer to foam while bottling, filling up the headspace until capped, and thus purging the bottle entirely.

To make that happen you can sometimes rely upon the residual CO2 in the beer post fermentation, or try other things like lightly carbonating in a pressure barrel then bottle from there.

I ended up avoiding the problem by getting into kegs and my hoppy beers are much better for it.

 

[The-Engineer-That-Brews]

get the beer to foam while bottling, filling up the headspace until capped, and thus purging the bottle entirely.

Good point that!

 

[JockyBrewer]

Good point that!

It’s how even the mega breweries do it - on their bottling lines they fire a micro jet of water into the top of the bottle to create foam, then cap on that… albeit it’s all done on an automated line in the blink of an eye and at a rate of 1000+ bottles per minute.

Jetting: The Oxford Companion to Beer Definition of jetting

 

[cushyno]

Some people individually prime their bottles with sugar, full with beer and then shake to dissolve the sugar. Don't do this! Any shaking just causes more beer to be exposed to the small amount of oxygen in the bottle head space.
This also expand why some beer mails end up oxidised as they have been shaken up repeatedly in transit.

Splashing the beer into your keg/PB/bottles will introduce oxygen, sometimes enough to oxidise. Rack your beer through a tube or bottling wand directly to the bottom of the container without splashing or pouring down the side.

Foaming as mentioned does force out excess air.

 

[RichardM]

Some people individually prime their bottles with sugar, full with beer and then shake to dissolve the sugar. Don't do this!

Just to be clear, the sugar will dissolve of its own accord. It's the shaking that you shouldn't do, not the priming in the bottle.
Although batch priming is easier than priming each bottle individually.

 

[cushyno]

Just to be clear, the sugar will dissolve of its own accord. It's the shaking that you shouldn't do, not the priming in the bottle.
Although batch priming is easier than priming each bottle individually.

Yes precisely. Bottle priming is fine, sugar is fine, just don't shake the bottle. Thanks for the correction.

 

[Polcho]

I too read everything I could get my hands on before my first AG brew (about this time last year, if I remember correctly) - I was petrified of getting it wrong (and I did, slightly) but the beer was still better than anything else I'd brewed by a country mile. Well WELL worth the effort, and it's easier than you imagine.

What are you planning to brew? Unless you're doing a lager, I wouldn't worry too much about oxidisation if I were you - it's highly unlikely to be a problem. It IS worth chucking half a crushed up Camden tablet into your water before it gets anywhere near the grains though as chlorinated tap water is a devil.

I think I will go with the Camden tablet. I have ordered this from Malt Miller Tasty Table Beer | The Malt Miller
It is all a bit daunting, exiting though

 

[Polcho]

Handy few pointers there, foam in the head space and not shaking, which I would have done.
Just wondering how to get it to foam if I’m not to splash though.

 

[RichardM]

Yes precisely. Bottle priming is fine, sugar is fine, just don't shake the bottle. Thanks for the correction.

I wasn't trying to correct you, just clarifying in case anyone misunderstood.

 

[RichardM]

Handy few pointers there, foam in the head space and not shaking, which I would have done.
Just wondering how to get it to foam if I’m not to splash though.

I was wondering that as well!