O2 Aeration in the kettle?

[mthhurley]

Hello all!
I just listened to the podcast about aeration and had a question.

I use o2 with a stone and give a 30 second shot in the fermenter. One problem I've had is the bubble up/foam over when doing that in the fermenter. So I'm wondering, once I chill down my wort in the kettle (copper coil chiller), can I oxygenate it in the kettle and then drain it into the fermenter and pitch? The larger surface area available in my kettle, I would suspect, will alleviate my bubble concentration issue in the neck of the carboy.

Thanks all, looking forward to spending time here and enjoying this new found podcast series.

Mike

[TheDarkSide]

I can't comment on using a stone, but once the wort is cooled down enough, I usually lift the immersion chiller up and down in the kettle to help cool it down and also help aerate.

[ajdelange]

If you are getting that much foam your O2 flow rate is way to high. The best procedure is to control the flow just to the point where bubbles break the surface and then use that rate subsequently. Obviously a flow meter, which can be had for a few bucks, is a good way to insure that the flow is the same each time.

The proteins in the foam you generate by oxygenation will not be available for head formation later in the glass so that's one reason not to allow that much foam to form. Also, if the bubbles are breaking the surface the O2 isn't dissolving in the beer and you are wasting it.

[brewinhard]

If you are getting that much foam your O2 flow rate is way to high. The best procedure is to control the flow just to the point where bubbles break the surface and then use that rate subsequently. Obviously a flow meter, which can be had for a few bucks, is a good way to insure that the flow is the same each time.

The proteins in the foam you generate by oxygenation will not be available for head formation later in the glass so that's one reason not to allow that much foam to form. Also, if the bubbles are breaking the surface the O2 isn't dissolving in the beer and you are wasting it.

Very interesting AJ! i too have let my aeration rage wildly. Although I have observed no ill effects from this involving head retention or foam formation, but I do see where it could be an issue. I guess it's probably the same thing where if you swirl the fermenter too often, every time the beer foams you are breaking the protein bonds necessary for foam formation which can never be re-formed. I would think this would have to be done many, many times to see any true ill effects, but I will not be the one to test this... Good to keep in mind though for generally brewing better beer!

To answer the initial question - YES! I think you could aerate in your kettle and then transfer the wort to your fermenter. I in fact have done this before and had good results. Go for it!

[mthhurley]

If you are getting that much foam your O2 flow rate is way to high. The best procedure is to control the flow just to the point where bubbles break the surface and then use that rate subsequently. Obviously a flow meter, which can be had for a few bucks, is a good way to insure that the flow is the same each time.

The proteins in the foam you generate by oxygenation will not be available for head formation later in the glass so that's one reason not to allow that much foam to form. Also, if the bubbles are breaking the surface the O2 isn't dissolving in the beer and you are wasting it.

The way my little O2 tank works basically is either on or off, there's no flow control. It's the regulator from Northern Brewer and I swear, nothing flows until I open the knob over to full stop. I'm using a stainless stone and it's probably one 4" deep into the fermenter. I'm considering getting a wand to get down to the bottom to get more distribution. Would that make any difference?

Thanks,

[ajdelange]

Although I have observed no ill effects from this involving head retention or foam formation, but I do see where it could be an issue.

Can't honestly say I've ever observed this effect but apparently that's what they teach at Siebel.

I'm considering getting a wand to get down to the bottom to get more distribution. Would that make any difference?

Definitely. If you are only 4" deep the O2 is only traveling through 4" of beer before breaking the surface to be lost to the air. The deeper you place the stone the longer the bubbles' trips to the surface, the more time for interraction and the more will dissolve.

Even if your valve is ON/OFF only you can still regulate flow. Pinching the hose with a small C-clamp, for example, will allow you some, if not fine, control. Someone posted a link to an e-bay site where they were selling a nice little flow meter with needle valve for a very reasonable price. I can't find it in cursory search but perhaps someone else will remember. And, of course, you can get flow meters from sources like Cole-Parmer (but forget the "reasonable price" thing).