When is oxidation a greater risk?

[Just-a-Guy]

When moving the wort from the brew kettle to the primary fermenter?

Or when moving from the fermenter into the bottling bucket?

Is the risk of oxidation present at both stages? Equally? Or is oxidation more a concern for the fermentation process and less of an issue once the gravity has stabilized?

Thanks for any input.

Mark

 

[eeverwine]

When transferring cooled wort from the kettle to the fermenter it is necessary to aerate the wort for good yeast production and healthy fermentation. I use a paint stirrer on a drill to whip a ton of oxygen into the wort, some fancier people even use pure oxygen and shoot it in there. When you're going post fermentation into your bottles you want to be careful not to aerate your beer too much as you could end up with oxydation off flavors down the road in your final product.

 

[xjmox14x]

You want to oxygenate the wort prior to pitching the yeast... the yeast need oxygen. After fermentation has stopped is when you need to worry about oxygenation.

 

[Homercidal]

After the initial fermentation, when the Yeast have picked up the available O2 and reproduced is when you want to start being careful.

 

[brewski08]

you never want to oxidize any part of your beer. Oxidation of your beer usually comes from excess splashing of your beer's surface area.

However, you do want to AERATE your wort once it's under 80F. Once it reaches a cool temperature under 80 F, oxidation does not occur. You want to aerate your beer before putting it into the primary in order to give the yeast their oxygen needed in order to chomp away at all them tasty sugars. Mmmm.

 

[aiptasia]

As stated, yeast are aerobic and require oxygen to do their thing. When you're first putting your wort into the primary, it's a good idea to oxygenate it so the yeasts will have plenty of O2 to do their thing.

After that, oxygen is a bad thing and it's best to avoid disturbing your beer as much as poosible. When racking to a secondary or bottling bucket, use a racking cane with a hose that goes all the way down to the bottom of the secondary/bottling bucket. This will keep the beer "underwater" and avoid splashes from getting oxygen into the beer while you rack it.

A beer that has been oxidized will taste like wet leather or cardboard on it's way to turning into vinegar. A paper/leather off flavor in your beer is a sign that it's been exposed to the O2 at some point.

 

[Just-a-Guy]

Ah, right, ok. I think I should have known that, but spaced on it somehow. Thanks, guys.

FWIW, my concern came from bottling last night (a red ale from a LME kit). I was using an auto-siphon to move from the carboy to the bottling bucket. And twice (damnit!) the siphon ran out (I didn't push it down far enough) and air got into the siphon. When I restarted it, it bubbled a fair amount in the bottling bucket, as the air from the siphon worked its way out. This has me a bit worried. The beer tasted quite good and I would hate to mess up this batch (been having problems with the other batches).

Thanks,

Mark

 

[Homercidal]

I wouldn't worry too much about it. Obviously you want to minimize that sort of thing if possible, but that much should not pose a concern if it's a beer you plan to drink right away.

Best thing at this point is to RDWHAHB and see if you can taste any oxidation in your beer over time.

 

[Just-a-Guy]

Thanks, Homer. That's reassuring and confirms what I suspected. If this batch tastes as good as I think it will, it won't last very long.

 

[Realidad]

Dont worry about Oxygen too much. When you put the kettle wort into the fermenter there is enough oxygen in the air for the tiny microscopic yeast to breath. Adding more oxygen is just being exteme and pedantic as it might help the yeast out a bit but its a lot of effort, time and money. Im pretty sure there is a good area in your fermenter for oxygen.

The part of the process where oxygen works against you is in the secondary and when fermentation has completely stopped. After 3 or 4 days I open the top of my Fermenter and remove my krausen kollar which revitalises the O2 supply and is ok for the beer also as the layer of brew is protected by an invisible layer of Co2.

Nothing to worry about too much in the primary, avoid in the secondary.

PS, EXCEPT IF THERE ARE POLLUTANTS IN THE AIR WHICH COULD INFECT THE BATCH>

 

[BamaRooster]

Post fermentation is where the risk lies, IMHO.