aeration?

I'm soliciting opinions...

Can adequate aeration of a full-boiled wort be achieved through splashing while siphoning into the fermenter and agitating the fermenter, or is some sort of forced aeration system (aquarium pump or oxygen) necessary for good yeast performance?

I'm convinced that one may be able to achieve adequate aeration thru splashing while siphoning, or pouring into your fermenter. Others will likely argue that your wort and yeast may be doomed to an untimely demise without the use of some aeration tool.

Personally I'm using Gravity to achieve adeqaute aeration for my 10 gal batches. It hasn't failed yet, In fact I have been brewing for over ten years and have never had an issue with aeration. (if it ain't broke...) I would guess that you would get optimum aeration thru the use of an aeration stone, or other device. my two cents FWIW.

cweston said:

I'm soliciting opinions...

Can adequate aeration of a full-boiled wort be achieved through splashing while siphoning into the fermenter and agitating the fermenter, or is some sort of forced aeration system (aquarium pump or oxygen) necessary for good yeast performance?

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I honestly don't know how to answer your question...probably yes, but an oxygen tank is $7, and the airstone/tubing/regulator is $29, and both of those are little enough that in this case it's easy to just spend the money and get the best, IMHO of course.

cweston said:

Can adequate aeration of a full-boiled wort be achieved through splashing while siphoning into the fermenter and agitating the fermenter, or is some sort of forced aeration system (aquarium pump or oxygen) necessary for good yeast performance?

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I believe that this will give you sufficient aeration for ales. You need about twice this amount for lagers. That's when I would urge the purchase of an aeration/oxygenation system.

Kai

I give the carboy a really good shake for 5 minutes and my fermentation is always great.

I pour between buckets (bottling pucket and fermentation bucket that came with the kit) between 5-10 times. Always seems to get good aeration. In fact, I had immediate fermentation on my last brew, and it was from a starter (non even on an old yeast cake). Seems good enough to me!

My thoughts...
1) My first few batches I didn't aerate at all...didn't know about it. They did ferment, but I'm too far removed to remember how the flavor was. I thought it was great.
2) Air doesn't have that much oxygen in it...at least not compared to pure oxygen (duh), so shaking/pouring can't be as effective as direct injection.
3) This article: http://byo.com/departments/1410.html (an excellent article on head formation/retention) leads me to believe that shaking the fermentor could use up some of your 'foam capacity' in the finished product.

Basically, I'm with El P...it's worth the $35-40 for an oxygenation system to me, but I guess more homebrewers are making beer without them than with them, so they're hardly essential.

I like the oxygen + aerator technique but, yea your into about $40 to use this. I started using one 5 batches or so ago. Before that I used the strainer and then an aquarium pump to blast air in. Lots of big foam. I have not seen a noticable ferment change between each technique however.

The O2 setup is nice and probably the easiest approach. Turn it on and let it gently aerate. But the one that costs $ for each batch. Ultimately I like to do what the big boyz do for what I can afford. This is one of those things...

Baron von BeeGee said:

My thoughts...
1) My first few batches I didn't aerate at all...didn't know about it. They did ferment, but I'm too far removed to remember how the flavor was. I thought it was great.

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One thing to bear in mind is, that bottled water already contains lots of oxygen. If you use a significant amount of this to top off your wort (partial boils), then you are already good to go

Kai

Kaiser said:

One thing to bear in mind is, that bottled water already contains lots of oxygen. If you use a significant amount of this to top off your wort (partial boils), then you are already good to go

Kai

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That's very true, but I even went to a full-wort boil fairly quickly (2nd batch when I was kicked off the stove) and still didn't aerate the first couple. Although I did just tip them into the fermentor which probably helped.

There's a lot of leeway in this hobby and it ultimately comes down to where you draw the line in the sand. I'm a bit OCD with certain things, and hence make good size starters and aerate with O2.

What would be the most obvious signs of inadequate areation in a finished product? Poor attenuation and a higher final gravity than normal? Would you taste the difference? Less head retention?

According to one of the techs at Wyeast, O2 injection during transfer gives about 33 ppm, bulk aireating using a pump and air, 14 ppm, shaking/splashing 6 ppm. This is more important for high gravity ales, as the yeast need all the help they can get.

Everything you should know about aeration and starters is right here...

http://maltosefalcons.com/tech/MB_Raines_Guide_to_Yeast_Culturing.php

jeffg said:

What would be the most obvious signs of inadequate areation in a finished product? Poor attenuation and a higher final gravity than normal? Would you taste the difference? Less head retention?

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In general, sluggish fermentation and ester production can be results of inadequate aeration.

Kai

Fusel production can also be limited with good aeration (or I should say oxygenation).

At 64 deg F. the solubility of oxygen in water is 9.5 mg/L or approximately 9.5 ppm. That means if you aerate with an aerating stone and pure O2 you're going to lose oxygen into the headspace of your fermentor until equilibrium is reached.
You can calculate the the equilibrium concentration between the air and the wort using gas transfer equations, but I can't seem to find the correct one in my notes right now to do it. Assuming that your fermentor is sealed, you're going to have an equilibrium value of something between 33 ppm and 9.5 ppm after aerating with pure O2 because some of the O2 in the wort will offgas into the headspace until equilibrium is reached. I'm not sure exactly what that is, and its not necessarily 1/2 of the sum of the two values, as there is a partitioning coefficient--Henry's Law Constant involved. Unless of course you have pure oxygen in your fermentor headspace...

Just began to use oxygen recently and I get a more rapid and vigorous fermentation with oxygen. I had always just shaken the stoppered carboy in my lap for 5-10 minutes and the fermentayion/beer seemed fine. In fact I do not use an aeration stone and tubing. I flushed the head space of my 6.5 gal. carboy (with a 5.5 gal batch) with 100% O2 a shook it for just 1 minute. The start of fermentation was more rapid and then more vigorous than ever before but it may have been a better yeast starter culture. I'll need tubing and a stone for a 6 or 6.5gallon batch.

El Pistolero said:

I honestly don't know how to answer your question...probably yes, but an oxygen tank is $7, and the airstone/tubing/regulator is $29, and both of those are little enough that in this case it's easy to just spend the money and get the best, IMHO of course.

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Where do you find these oxygen tanks? Do they come with valves appropriate for this?

Megiddo said:

Where do you find these oxygen tanks? Do they come with valves appropriate for this?

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They are in the welding section of HD/Lowes. But they don't come with a regulator.

Kai

Megiddo said:

Where do you find these oxygen tanks? Do they come with valves appropriate for this?

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As Kai said, the tanks are in the welding section of any hardware store, and you can get the airstone, tubing, and regulator in a kit from any online or LHBS.

Kaiser said:

They are in the welding section of HD/Lowes. But they don't come with a regulator.

Kai

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wahoo!!! I was hoping you guys were talking about those tanks. Now to get it hooked up to a hose. I have hose and stones. Up till now I've used aquarium stones and a regular aquarium pump. But I've never liked the idea of un-filtered air being pumped into the wert.

But boy does it increase the krausen.

So, how do you avoid cold-side aeration when using a stone? I thought that once the yeast was pitched, aeration was a bad thing? Do you guys only aerate until the fermentation gets underway?

sonvolt said:

So, how do you avoid cold-side aeration when using a stone? I thought that once the yeast was pitched, aeration was a bad thing? Do you guys only aerate until the fermentation gets underway?

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The latter...aeration is not a problem after the wort is chilled and before the yeast has gotten going. There is even some question about whether or not HSA is a problem at the homebrew level, but it's easy enough to avoid so why tempt fate.

sonvolt said:

So, how do you avoid cold-side aeration when using a stone? I thought that once the yeast was pitched, aeration was a bad thing? Do you guys only aerate until the fermentation gets underway?

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I only aerate before pitching. And in the Starter (well, I haven't here, but my next batch will).

Good article on aerating the Starter: http://maltosefalcons.com/tech/MB_Raines_Guide_to_Yeast_Culturing.php

Someone else posted this recently... not my find.

Megiddo said:

Now to get it hooked up to a hose.

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Quoting myself here... but I think I found a nice regulator:

http://morebeer.com/product.html?product_id=16606

The word "adequate" is key. You can have fermentation after a lag time and risk off flavors from other little beasties doing the nasty before the yeast kicks their butt, but to really get things rolling I say you need to get more aeration then you will get by splashing.

Spend the money and say good-bye to the problem.

Brewpastor said:

Spend the money and say good-bye to the problem.

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Or you just knock over that old lady and get her O2 tank . Or how did you get yours BP .I saw one in a pricture of your set-up.


Kai

How many uses do you get out of one of those tanks you buy at Lowes?

jerly said:

How many uses do you get out of one of those tanks you buy at Lowes?

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With mine, I have done 8 batches (including starters) so far and the bottle is still not empty. The first batch I even aerated for 15min b/c i misread the instructions. Usually I oxygenate 1-2 min for primary fermentation and 10-20s for starters.

Kai

Megiddo said:

Quoting myself here... but I think I found a nice regulator:

http://morebeer.com/product.html?product_id=16606

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That's the one I got.

Kaiser said:

Or you just knock over that old lady and get her O2 tank . Or how did you get yours BP .I saw one in a pricture of your set-up.


Kai

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You know how churches are full of old widows on oxygen? Well, it is amazing what a powerful tool guilt can be with someone who is already seeing a slight glow at the end of the tunnel...

Actually, mine came from a friend who has a home medical business. Merry Christmas to me! You can get a tank and so forth from a welding shop. The medical vs industrial O2 debate is a whole other thread, but that would be my suggested way to go.

Brewpastor said:

You know how churches are full of old widows on oxygen? Well, it is amazing what a powerful tool guilt can be with someone who is already seeing a slight glow at the end of the tunnel...

Actually, mine came from a friend who has a home medical business. Merry Christmas to me! You can get a tank and so forth from a welding shop. The medical vs industrial O2 debate is a whole other thread, but that would be my suggested way to go.

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I saw them in the welding shop too, when I got my last CO2 refill. But having that much oxygen available only tempts me to use to much of it in my starters. And I read that to much pure oxygen can be a bad thing, because it can make the yeast age much faster. But that is only if you would use lot of it.

Kai

Kaiser said:

Or you just knock over that old lady and get her O2 tank .
Kai

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Great Idea!!