Aeration

I'm getting ready to brew my second batch today, a Hop Devil Clone.
I have an aeration question. How much?
I did a search and got varying techniques. Some just pour the wort into their cool water and consider that enough while others mix it up. Still others close the fermenter and shake it and others buy fancy mixers to whip it up to a bubbly head.

Too little? Too much?

Thanks

Tommy

Brewno said:

Too little? Too much?

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As long as its a one-shot infusion, no matter how its performed, will never be too much. Aeration is a vast subject with no hard and fast rules. Not all brewing yeast strains have the same oxygen requirements for satisfactory fermentation. Then there is the percentage of O2 in air as opposed to some what pure O2 in medical or purer O2 in welding tanks. I personally started out pouring very cold sanitized water from 7' above my fermenter to aerate. Now with full boils, I add 30 seconds of medical O2 through a 0.5 micron stone. Try whatever you have available and see what your lag time is compared to others.

Good luck,
Wild

^^^ what he said...

If you are not doing a full boil then chances are the un-boiled water will have enough O2 in it that you will more than likely be okay. You don't want to aerate hot wort though! Make sure it's cooled before you aerate to avoid oxygenating the wort.

I do full boils and once the wort is cool and in the primary I stir the crap out of it with my sanitized mixing spoon for a few minutes. Soon I have a bunch of foam and call it a day and pitch the yeast. Never had any problems with lag time..

I don't do full boils, but I separatly boil and cool the water that I user to make up 5+ gallons. I use a plastic primary, so, before I pitch the yeast, I slap the cover on, hold my thumb over the airlock bung, and shake the primary like a drink mixer for a bit. I do all this AFTER making sure that the combined mixture is down to temp (in the 70*F range). Then I crack it open again and pitch, cover, shake again, and add the airlock. It works fine for me, and I have gotten some great response times and ferments. You just need to make sure that when you are opening and closing the primary a couple times, that you take care to not let anything in, and keep the lid sanitary.

Ahhh, make sure it's cooled.
Thanks, so in other words, take my wort off the stove, cover and cool it in a sink of ice water for awhile, then pour it into my fermenter of cool water and when it's cooled to pitch temp, aerate?
Didn't know that.....thanks.

Tommy

You got it!

Damn. After I took my wort off the stove today I put it in a sink of cold water and stirred it around a bit to cool it down. It wasnt until after I did this that I realised not to aerate hot wort I'm guessing this was a bad move? I dunno. I didnt like shake it around, I just stirred it. Do you think I oxygenated my wort? What happens if it is oxygenated?
I hope I didnt wreck my brew

You want oxygenated wort. You don't want HOT oxygenated wort. When cooling, it is best not to agitate the wort at all. At most, I slowly move my wort chiller up and down a coupl inches to clear the thermal barrier that can form around the coils (cold water/hot water form find of a wall and prevents hot from contacting colder coils.) I do not stire it until it is below 80*F. Then I stir it hard to whirlpool it (debris collects in middle). Then I do what I mentioned in my 1st post.

The actual numbers from Wyeast labs:

Shaking/stirring 6 ppm O2
Air & stone 12 ppm O2
Oxygen & stone 33 ppm O2

The more oxygen the better, you get more yeast. They all work.

Truble said:

You want oxygenated wort. You don't want HOT oxygenated wort.

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Right theory wrong wording
You don't want to oxygenate wort ever... You do want to aerate the wort. If you aerate hot wort you will run the risk of oxygenating it. When you aerate the wort you add O2 into the mix.. But when you oxygenate it you are actually fusing the O2 to the wort. This is released but not as fast as when it's aerated cool... If you did it hot the O2 will be released after fermentation has started and that's the time you do not want the O2 in there...

If you just stirred it around a little when hot it's prolly not going to be a big deal. If you let loose on it when it was 140F then you might get some off flavors.

Corrected. That is what I meant, though the letter mis-spoke.

Mishkin said:

What happens if it is oxygenated?

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If you "aerate" the worth while it is still "hot", as it is cooling down to yeast pitching temperature, there is a window of opportunity for "bad" bugs to find oxygen and thrive before yeast takes over and wins the battle.

There is also "too much aeration" possibility. If there is more oxygen than yeast could consume, it will stay and result oxidation. (Statement is not based on my experience but reading few books I have as reference sources. If disputed, I'l look it up to provide citation.)

The way I look at it is this. Have you ever stared at all the freaking dust suspended in the air when sunlight streams into your home? That stuff is definitely far from sanitized. The more you move your wort around the more you chance getting significant amounts of nasties into the wort. That's why aeration systems have filters on them.

When I use my wort chiller I have the cover on, gently agitating the wort every so often w/o surface agitation so I don't get the temp. barriers.

Wait till your wort is cool, then siphon using a small tube at the top of your bucket/carboy (with lid on if bucket) and make some bubbles. Then stop your airlock hole and shake for a bit...as long as the wort is <80deg. you should aerate real well.

Me, I just broke down and bought an O2 aeration system which was on sale a few days ago...

YMMV?

The biggest difference in my lag time came with a starter but by using two air stones with a pre filter on them I shaved another 5 hours off of my lag time. (spending special time to sanitize the stones and hoses) It has made a difference.

Sephro said:

Right theory wrong wording
You don't want to oxygenate wort ever... You do want to aerate the wort. If you aerate hot wort you will run the risk of oxygenating it. When you aerate the wort you add O2 into the mix.. But when you oxygenate it you are actually fusing the O2 to the wort.

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With all due respect, aeration and oxygenation are effectively the same thing. They both result in dissolving oxygen into the wort which is desirable before fermentation has started.

What you want to avoid is oxidation, which is the chemical bonding (or fusing) of oxygen with the wort.

-a.

Brewno said:

Some just pour the wort into their cool water and consider that enough

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That is MOST CERTAINLY not enough. On top of areation you want to make sure things are mixed up well too. I got this thing that attaches to my drill and it works great. All you need to do is shake it a bit. When you get real tired, shake it for a bit more and that should be enough.

ajf said:

With all due respect, aeration and oxygenation are effectively the same thing. They both result in dissolving oxygen into the wort which is desirable before fermentation has started.

What you want to avoid is oxidation, which is the chemical bonding (or fusing) of oxygen with the wort.

-a.

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Well... I can understand why you say that aeration and oxygenation are the same thing.... but I also say that I have never seen the word oxygenation used when the author meant aeration. Hmm... actually I can't even say I have seen the word oxygenation used. Perhaps the word is too close to oxidation so it is avoided.....

Beer Snob said:

That is MOST CERTAINLY not enough. On top of areation you want to make sure things are mixed up well too. I got this thing that attaches to my drill and it works great. All you need to do is shake it a bit. When you get real tired, shake it for a bit more and that should be enough.

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I have to say that I don't work anywhere near that hard at aeration and I get good results.

partial boil goes on top of the cool water (although I cool the wort to 80-ish before I add it to the carboy) and I shake for a while in the carboy to get the water throughoughly mixed. But not till 'I get tired'. I can't imagine I shake the thing more than a minute or 2 tops.

I have a stone on a line with a filter hooked up to fish tank pump. I just drop it in and let it go until the wort is pitch temp..... since switching from the shake it up method I found I get starts almost as fast as a starter just pitching the smack pack or vial. There is a noticable difference.

TekelBira said:

There is also "too much aeration" possibility. If there is more oxygen than yeast could consume, it will stay and result oxidation. (Statement is not based on my experience but reading few books I have as reference sources. If disputed, I'l look it up to provide citation.)

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I love building gadgets for my brewing and would like to make an inline aerator, but the guy at my LHBS said I needed to be careful not to over aerate the wort. Does anyone know how easy it is to over aerate? I am using O2 but could switch back to filtered air if there is an issue. I also spoke to a brewer at a local brewery this weekend and he didn't think as a home brewer that I could get too much 02 in there.

Kyle

kthorson said:

I love building gadgets for my brewing and would like to make an inline aerator, but the guy at my LHBS said I needed to be careful not to over aerate the wort. Does anyone know how easy it is to over aerate? I am using O2 but could switch back to filtered air if there is an issue. I also spoke to a brewer at a local brewery this weekend and he didn't think as a home brewer that I could get too much 02 in there.

Kyle

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Chris White (of White labs) has been makling the brewing confrence circuit, at a confrence for homebrewshop owners last week (to which the owner of my lhbs attended and told me about his presentation), as well as on Basic brewing radio, and at NHC, he is recommending a 2 minute blast of o2 (from an oxygen bottle) as being the correct amount in a five gallon batch before pitching....I don't know how that translates to parts per million, but I'm sure Chris mentioned it.

(Chris also is saying that in beers with an OG of 1.060 or higher to give your wort another blast within the the 10-12th hour after pitching the yeast-Contrary to what we've all been taught, but you gotta figure that if the makers of the yeast are pushing this, then they know best.)

And really with Wort there is no danger of over aerating it...it isn't till it is beer that there is a danger of oxydizing it (and that supposedly requires a lot of ppms worth to affect it as well.)

Thanks for the response! I think I will go ahead and add my aerator inline and see how it goes. I really like the idea of pumping the wort from the kettle through a CFC and adding O2 right before the fermentor. Should save me quite a bit of time. Although that is beer drinking time I am cutting into... I might need to rethink this!

Kyle

kthorson said:

Thanks for the response! I think I will go ahead and add my aerator inline and see how it goes. I really like the idea of pumping the wort from the kettle through a CFC and adding O2 right before the fermentor. Should save me quite a bit of time. Although that is beer drinking time I am cutting into... I might need to rethink this!

Kyle

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LOL...

SO will you post your designs...it sounds interesting..

It seems to me that aeration is up there with batch vs. fly sparging in terms of religion to homebrewers. Based on my experience, there is "optimum" oxygenation/aeration, and then there is "good enough" aeration, which I personally define as relatively short lag time and good attenuation.

My old method was a wire whip in the boil kettle after chilling to pitching temperature, like this:

The wire whip, in conjunction with pouring the wort into the carboy through a sanitized strainer and funnel, and pitching a large, healthy yeast culture, got the pictured 1.088 OG Imperial stout to krausen within six to ten hours (I can't guess any closer, since I was sleeping). Attenuation was 75% or so, just exactly where it should have been.

When I graduated to a keggle for boiling, I revised my aeration method to include a perforated tube at the end of my drain line to aspirate air into the stream entering the carboy, as described in another thread The highest gravity I've brewed with that rig was 1.055. After pitching one pack of non-rehydrated dry nottingham, I had krausen within six hours.

Are those methods optimal? Maybe not, but in terms of a trade-off between complexity, investment in hardware, and an easy brew day, I'm happy with these two methods, which I think are good enough for me.

So, OP and other new brewers, like most things in the brewing craft, there are at least 57 ways* to aerate your wort. 20+ of them are probably pretty good, and 3 or 4 of them are probably optimal. Pay attention to your lag times, and try to find something that works for you.

*80% of statistics are made up on the spot.

OK, so I am pretty guilty of wanting to add a little bit of "coolness factor" to my brewing equipment. Its definitely going to be over kill, there is no doubt about that. hehe

I am currently doing full volume bolls and using an immersion chiller to cool down. Then I just use a .5 micron stone with a hardware store bought O2 tank. It works really well the way it is except for the time when the stone came off in the fermenter... only one brew at a time when that happens....

The aeration setup I bought is just a bad design, instead of a hose barb on the air stone it uses a little nut to cinch down the hose using only pressure.

Revvy,

This is the site that sparked my interest with the inline aerator... see the picture at the bottom right of the page: (http://www.oregonbrewcrew.com/cfc/cfc.html) It just looks cool.


Kyle