Aerating wort

[Beer-lord]

I finally got an oxygen system to aerate my wort. Just curious on how long those of you who use this method aerate. Most of what I've read says 60 seconds and too much is not helpful and may be harmful.

[dad2all5]

I was thinking of going to the pet store for a air pump and bubbler from the fish tank section? I was wondering if this would work. This type of pump does not use external air. How about the stoe bubbler they some in all kinds of sizes, to clean I would but in soome onestep and bubble away for a few minutes?

[Beer-lord]

Here's a few ideas that might help:
http://byo.com/aeration/item/1894-aerat ... techniques

http://beersmith.com/blog/2010/01/19/ae ... wing-beer/

http://morebeer.com/category/wort-oxyge ... ation.html

[dad2all5]

Very cool the above links all helpful. Thanks Beer Lord.

[Kealia]

Hey Paul,

I've settled on 45 seconds on a 2.5G - 3G batch and about 90 seconds on a 5G batch. From what I understand you CAN over oxygenate, but it's not easy to do. You'd have to go REALLY excessive for that to happen. I heard opinions varying from 30 seconds to 90 seconds and just played around a bit to see what I thought worked best.

I turn it on just high enough for the bubbles to break the surface because the way I see it, if it's aggressively bubbling out of the wort, it's not being absorbed.

But that's just me.

[FrozenInTime]

I do mine for an average 30-35 seconds on LBKs and LBCs and have had success. 5 gals I go 60 seconds.

[mashani]

The biggest issue with over oxygenating that I am aware of is that if you put a ton in there and there are enough nutrients in the wort you can actually extend the growth phase of the yeast, as they then have more of everything they need to make more daughter cells. That translates to more lag time and more yeast character developed - almost the same as if you underpitched. It will ferment the crap out of the beer because of all the hungry daughter cells, so you will end up with a lower FG then you expected too. So between those things the character of the resulting product will change.

I'm pretty sure any excess oxygen will be scrubbed during active fermentation regardless. Actual "oxidation" is not really a concern here I think.

[RickBeer]

I'd be interested in learning if anyone has ever made two identical batches, side by side, where they aerate their normal way and aerate with oxygen and compare the two end results. In other words, proved that they can tell the difference, in a blind taste test, between the two batches (or validate that the O2 aerated batch attenuates lower). Just curious.

As we all know, it's pretty hard not to make beer no matter what you do. Everyone swears by different methods and everyone says their method works best for them. I'm just curious if someone on the forum has done the above and proven to himself/herself the results, that's all.

[Beer-lord]

Everything I read tells me there's no need to aerate the wort for dry yeast but many people do anyway.
My problems lately have been with low attenuation. My FG is not where it should be. This has been with both wet and dry yeasts though I seem to do better with dry yeasts. So, today, using liquid yeast, I'm going to see if aeration helps any.

[Kealia]

I'd be interested in learning if anyone has ever made two identical batches, side by side, where they aerate their normal way and aerate with oxygen and compare the two end results. In other words, proved that they can tell the difference, in a blind taste test, between the two batches (or validate that the O2 aerated batch attenuates lower). Just curious.

As we all know, it's pretty hard not to make beer no matter what you do. Everyone swears by different methods and everyone says their method works best for them. I'm just curious if someone on the forum has done the above and proven to himself/herself the results, that's all.

I've not done a head to head myself but if you have the time this is well worth the watch and deals with head to head tests at varying saturation levels:

[Beer-lord]

Gotta admit, after my first try aerating the wort, I'm not impressed. I pitched the yeast at 11:30 am today and so far, at 10:00 pm, I see no activity. I almost always see activity by now when I simply stir the crap out of my wort.
Actually, I know speed of activity IS NOT what aerating is all about but I kept reading how fast many people saw activity when using oxygen.

[FrozenInTime]

Personally, the only time I have seen a difference is when I pitch heavily on liquid yeast. I have not seen much difference between using oxygen or just whipping it hard when I use dry yeast. IMHO and limited experience (I lost my oxygen, forgot to turn it off last time I used it.... LOL)

[mashani]

Gotta admit, after my first try aerating the wort, I'm not impressed. I pitched the yeast at 11:30 am today and so far, at 10:00 pm, I see no activity. I almost always see activity by now when I simply stir the crap out of my wort.
Actually, I know speed of activity IS NOT what aerating is all about but I kept reading how fast many people saw activity when using oxygen.

It honestly doesn't make a lot of sense to me that folks always expect to see activity faster when aerating more or using pure oxygen. I think this is not really what caused it honestly. The extra oxygen is going to allow for more yeast growth, which means more lag time UNLESS the wort is lacking other nutrients that force the yeast to switch from growth mode to active fermentation. I'd bet that besides just aerating they also pitched a more robust starter or otherwise happier yeast, or are otherwise comparing apples to oranges.

Just like a stir starter the whole point of aeration is to encourage more yeast growth to insure a better fermentation. That's what a stir starter does... non-stop aeration! Yeast doesn't know the difference between a starter and your wort in the fermenter. It's growth process is the same.

There is going to be some kind of overlap point where the number of pitched parent cells + number of daughter cells created by some level of aeration and the growth phase switch to active fermentation is the same for a lower aerated wort (more stressful growth phase) and a more highly aerated wort (grow easily) where both show visible signs of active fermentation in around the same timeframe, just because they *have to* switch their metabolism once they run out of nutrients needed for growth phase... But these two fermentations are not the same, even though they "started" visibly at the same time... the one with more daughter cells is likely going to ferment out quicker and potentially attenuate better.

If you oxygenate the crap out of your wort, toss in nutrients and severely underptich your yeast, you will actually likely see more attenuation then if you pitched normally. Yeah I know that sounds wrong, but it goes back to the idea that your wort is not any different then a stir starter at that point, just all the daughter cells grow in your wort instead of on your stir plate and there is a lot more in your wort to grow with. You also will taste a lot more yeast profile due to all the extra daughter cell growth. The growth phase will take forever, but once it does start to ferment it will ferment like mad.

This in fact is the best way to recover an old yeast culture that is degrading. Make a very healthy wort, severely underpitch, be sure your sanitation is impeccable. The best cells will outcompete the lame ones, most of the daughter cells will be from the more healthy yeast... wash the results and you have potentially revived your old yeast.

[Beer-lord]

It is strange that this morning, I see no airlock activity but there is a somewhat thick head of krausen at the top so I should see some airlock movement soon.
I've based all my 'thoughts' on what I've read here and other places but my experience shows using liquid yeasts start slower than dry in almost every occasion.

mashani, I've had attenuation problems and that's my only reason for getting the oxygen kit. I'm curious as to if it helps. I've noticed that on a few of my batches, fermentation takes off fast and only lasts 1-2 days (which I've also read as normal) but if this slower activity means more of the yeast is doing it's work, than that'll be worth it.

I should add that I have this beer fermenting at a much lower temperature due to recent fusel problems so the fast fermentation very likely was due to heat and this, possibly slower fermentation could also be, in part, due to cooler temps. This is listed as 68-73 optimum temperature which I think is a bit too high.

[Kealia]

mashani provided a great response IMO.

Hold all judgments until this bad boy is DONE fermenting and I think you'll be pleased.

Not to treat you like a noob, but don't sweat the airlock activity. I had a really weird experience that I'll share. On a batch this past Spring I pitched my yeast into my Ale Pail, installed the airlock and then carried it into my fermenting closet. After 48 hours I had no activity and I got a bit worried so I pulled the lid off. There was almost an audible 'pop' when it came off.

Inside there was a thick krausen but when I picked it up I created some type of back suction/pressure that was preventing airlock activity. I put the lid back on and literally minutes later it was bubbling like mad. (If I had to do it again I would just remove the airlock and not the whole lid).

Anyway, worth a shot to see if that's the issue (pressure). Otherwise, I wouldn't sweat it at all, sir.