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General Category => Yeast and Fermentation => Topic started by: bo_gator on November 25, 2009, 06:27:25 PM

Title: Oxygen; too much, or not enough
Post by: bo_gator on November 25, 2009, 06:27:25 PM
Everyone always tells posters to aerate enough. So how much O2 is enough without using too much :?:

Most of the time I use 1 minute of red bottle O2 through a Williams' SS wand set-up for ales, and 2 minutes for lagers/high gravity beers. Is this enough, or not enough, or too much :?:   
Title: Re: Oxygen; too much, or not enough
Post by: denny on November 25, 2009, 06:52:16 PM
I think you'd need to be able to measure dissolved O2 in your wort before you could answer that.
Title: Re: Oxygen; too much, or not enough
Post by: lonnie mac on November 25, 2009, 06:55:54 PM
I do exactly like you with the red bottle and the williams wand except I go 2 mins for ales and lagers, 10 gal batches...

Not sure really how much o2 we are getting into solution with this method though. Seems like most of it is quickly expelled in bubbles as waste. I have been looking at making a nice in-line aerator myself.
Title: Re: Oxygen; too much, or not enough
Post by: denny on November 25, 2009, 07:09:15 PM
Here's an interesting design for a CFC with built in aerator....

http://www.oregonbrewcrew.com/cfc/cfc.html
Title: Re: Oxygen; too much, or not enough
Post by: tygo on November 25, 2009, 07:10:38 PM
I use the "Shake the living hell out of it" method.
Title: Re: Oxygen; too much, or not enough
Post by: lonnie mac on November 25, 2009, 07:20:07 PM
I use the "Shake the living hell out of it" method.

Sometimes I think I long for those days... I honestly think that I used to get some good aeration that way.
Title: Re: Oxygen; too much, or not enough
Post by: denny on November 25, 2009, 07:21:54 PM
I get such good aeration out of my cheap'n'easy Mixstir that I've never considered a more expensive/complicated method.
Title: Re: Oxygen; too much, or not enough
Post by: lonnie mac on November 25, 2009, 07:25:02 PM
I get such good aeration out of my cheap'n'easy Mixstir that I've never considered a more expensive/complicated method.

Funny subject! Because I'll be using my 3" mix stir Friday! This is one method I have been wanting to try...
Title: Re: Oxygen; too much, or not enough
Post by: denny on November 25, 2009, 07:27:57 PM
Cool!  You may never go back to the bottle, if ya know what I mean!  ;)
Title: Re: Oxygen; too much, or not enough
Post by: bluesman on November 25, 2009, 07:34:08 PM
Cool!  You may never go back to the bottle, if ya know what I mean!  ;)

+1

I use the same thing...high speed for 30 seconds. Really foams up the wort.
Title: Re: Oxygen; too much, or not enough
Post by: bonjour on November 25, 2009, 07:38:38 PM
I use my immersion chiller to aerate ALL my beers.  Works great and helps get the temp down to pitching temps.

Fred
Title: Re: Oxygen; too much, or not enough
Post by: lonnie mac on November 25, 2009, 07:41:28 PM
Cool!  You may never go back to the bottle, if ya know what I mean!  ;)

You are probably right... Although, I will do this in my kettle after chilling and then transfer to the fermentor in the fridge. I don't have the room to get in there to really do it... I'll give it a shot!

I am simply sick of buying the red bottles anyway. For the longest time, I used my Porter Cable air compressor, sterile filter and my wand... It too worked great but again I just didn't feel like I could get the saturation level that we need with that method either. Like Bo_gator was saying, how much is enough on our level... I have no idea, and I have misplaced my o2 level meter! :)
Title: Re: Oxygen; too much, or not enough
Post by: denny on November 25, 2009, 07:54:23 PM
how much is enough on our level... I have no idea, and I have misplaced my o2 level meter! :)

Why not judge that by beer quality?  After all, what else matters? 
Title: Re: Oxygen; too much, or not enough
Post by: mtbrewer on November 25, 2009, 08:04:22 PM
I use my immersion chiller to aerate ALL my beers.  Works great and helps get the temp down to pitching temps.

Fred
Could you elaborate more on that please?
I use a coat hanger and my drill.
Title: Re: Oxygen; too much, or not enough
Post by: bonjour on November 25, 2009, 08:07:14 PM
Sorry,

Once the wort is cooled down to 90F I rapidly move the chiller up and down thru the wort cilling it to (usually) below 70F and simultaneously aerating the wort.   Lots of foam

Works great, even on really big beers.

Fred
Title: Re: Oxygen; too much, or not enough
Post by: bo_gator on November 25, 2009, 08:08:26 PM
I get such good aeration out of my cheap'n'easy Mixstir

Never used one for aeration, but they work great at mixing honey and water together for a mead ;D
Title: Re: Oxygen; too much, or not enough
Post by: mtbrewer on November 25, 2009, 08:19:22 PM
Thanks, Fred. I do the same to help chill faster, didn't really think about it helping for aeration.
Man, I love to learn new stuff.
Title: Re: Oxygen; too much, or not enough
Post by: bonjour on November 25, 2009, 08:22:04 PM
I figure if it will for my 15%+ beers it's good. 


And it's cheap and easy

Fred
Title: Re: Oxygen; too much, or not enough
Post by: tubercle on November 25, 2009, 09:20:27 PM
I would think the amount of O2 that will dissolve into to the wort is limited based on the temp regardless on the method or device used.
Title: Re: Oxygen; too much, or not enough
Post by: bonjour on November 25, 2009, 09:23:04 PM
and pressure, but I have trouble controlling that

Fred
Title: Re: Oxygen; too much, or not enough
Post by: Kaiser on November 25, 2009, 09:38:10 PM

and pressure, but I have trouble controlling that

To some extend you do and it makes a difference. The O2 pressure in air is about 0.2 bar (~3 psi) while it is 1.0 bar (~15 psi) in pure O2. As a result you cannot overaerate with air and at common pitching teemps air saurated water wort is likely around 8-10 ppm. This is different with pure O2 where you can actually overoxygenate the wort. But pure O2 also allows you to get sufficient O2 into high graviy worts where you are limited with the use of air.

Kai
Title: Re: Oxygen; too much, or not enough
Post by: denny on November 25, 2009, 09:59:45 PM
And it's cheap and easy

Fred gets the Cheap'n'Easy Gold Star for today!
Title: Re: Oxygen; too much, or not enough
Post by: Thirsty_Monk on November 26, 2009, 01:01:52 AM
I am using this kind of gadget:
(http://i3.photobucket.com/albums/y59/SunneofKornne/brewing/aerator.jpg)
http://www.homebrewtalk.com/f51/cheap-easy-aeration-gadget-68218/

and sprayer at the end of transfer tube:
(http://www.northernbrewer.com/media/catalog/product/cache/3/small_image/135x135/5e06319eda06f020e43594a9c230972d/i/m/image_617.jpg)
http://www.northernbrewer.com/default/catalogsearch/result/?q=sprayer&x=0&y=0

It works pretty good.
Title: Re: Oxygen; too much, or not enough
Post by: denny on November 27, 2009, 05:31:00 PM
I used that kind of setup before I got a MixStir.  I found that the MixStir seems to be much more effective.
Title: Re: Oxygen; too much, or not enough
Post by: Matt B on November 28, 2009, 07:07:00 PM
I had built an inline aeration contraption out of PVC, using a bit of tubing and silicone caulk to attach my barbed aeration stone to the gadget. Drawbacks: couldn't bring the PVC above ~150, so had to permanently store it in sanitizing solution, and the caulking just didn't stick well enough, and the tubing popped off with the aeration stone. But for the $3 in PVC it cost me, good learning experience :)

I just rebuilt the contraption out of copper, should be far more solid now, and you can remove the aeration 'insert' for the lack of a better word, whereas the PVC one I made was more enclosed. Just finished it yesterday, and more of an initial prototype. Brewing today, so we'll see how it works. The only not as solid as it could be part was joining the barbed aeration stone to the 3" nipple. I tried using copper solder, no luck, it won't stick to the stainless, and didn't want to try brazing the stainless onto the brass as I don't know if that would work nor whether the stone itself would handle that kind of heat, so I used a bit of JB weld and shoved the barb inside the nipple. We'll see if it holds.

Q1: But I do have a couple questions for you guys: where the crap do you find the aeration stones with threads? No matter where I look or how much searching I do, I can only find the ones with barbs. However, if I were to make one again, I'm going to order a stainless steel 1/8" x 3" nipple so that I could shove the barb end inside it, and weld it together, the SS nipple was probably only a buck more than the brass one.

Q2: And since I enjoy making this type of stuff and providing custom equipment to my fellow home brewers, how many of you would like to have an inline aeration gadget? Would $60 + cost of aeration stone (as this is the big unknown) be reasonable? If interest is high enough, I'll make another one.


Title: Re: Oxygen; too much, or not enough
Post by: Matt B on November 29, 2009, 05:10:33 AM
Oh that was dreamy. Worked flawlessly.

Back to the original thread: oxygen; too much or not enough. I'm using an oxygen tank, and my method (to some bit of madness) was to start the oxygenation while I was still doing the recirculation of the wort through the CFC bringing it down to the final temp about a minute before I move to dumping it into the fermenter. Doing about 5 PSI using a 2 micron aeration stone. I get a nice milky color out of the wort.

However, like bo_gator (the original poster) I admit I have no idea if this is too little or too much, as all of the batches I've used this contraption in are still in the garage in kegs untapped. So before I get to drinking those..

Those of you who already use some sort of an inline aeration gadget, at what point do you begin your aeration, at what PSI and what micron level (and even the overall size) is your stone?

Obviously, too little oxygen means bad attenuation.

Too much oxygen, what would be the perceived effects? That way I know what to look for when I actually tap those kegs.

I'm considering going to a pump with a sanitary filter to push in plain old air, and as Kai pointed out, it's impossible to over oxygenate with that method, though O2 may still be better for a big beer. For those of you who use this method, what pumps do you use to force air in, and which do you like best?
Title: Re: Oxygen; too much, or not enough
Post by: seajellie on March 19, 2010, 02:05:51 PM
Has anyone experimented with "intermittent" aeration during early fermentation?

By this I mean occasionally aerating the wort with air pumped through a sterile filter. This would be through a pre-drilled hole in a bucket lid, so no need to worry about repeated risk of infection.

The point would be to potentially make up for the limits of the initial aeration of this system (say 8 - 10 ppm), to use on bigger beers, and do it (for example) for ten minutes twice a day up to the point of high krausen starting to form (or before). In red wine making for example, many authors say to not create an airtight primary so as to ensure oxygen for yeast, and of course there are all the commercial breweries that use open fermentation. I don't have such a sanitary condition in my basement, so that's a risky option to say the least...

A post Kai made in another thread got me thinking about this. His original post was in regards to the good results he had from continual aeration of starter wort (although I don't remember that he performed a taste test  ;)
Title: Re: Oxygen; too much, or not enough
Post by: Kaiser on March 19, 2010, 03:36:13 PM
A post Kai made in another thread got me thinking about this. His original post was in regards to the good results he had from continual aeration of starter wort (although I don't remember that he performed a taste test  ;)

Constantly aerating the yeast during propagation is different since the resulting beer is discarded. It may actually enable you to skip aeration of the wort that the yeast is pitched into. I haven’t tried that yet.

But early aeration of high gravity beers is certainly worth a try. You may want to watch out for a massive blow-off caused by the CO2 release when you introduce a lot of small air bubbles. A series of short 1-2s air bursts every 1-2 min might be better for controlling that blow-off

Kai


Title: Re: Oxygen; too much, or not enough
Post by: tygo on March 19, 2010, 04:07:04 PM

But early aeration of high gravity beers is certainly worth a try.

How early is early and when do you need to stop doing this so as not to risk causing oxidation in the final product?
Title: Re: Oxygen; too much, or not enough
Post by: denny on March 19, 2010, 04:13:37 PM
The ROT I'm familiar with is that you can aerate up to 14 hours after the first signs of fermentation.
Title: Re: Oxygen; too much, or not enough
Post by: bluesman on March 19, 2010, 04:29:56 PM
The ROT I'm familiar with is that you can aerate up to 14 hours after the first signs of fermentation.

+1

Presumably only during the growth phase.
Title: Re: Oxygen; too much, or not enough
Post by: seajellie on March 20, 2010, 01:42:04 AM
Thanks for the info guys, I'll give my next bigger beer (a Belgian ale) a bit more aeration like this.

The good thing about experimenting with Belgians, ya' can always just claim that "it's character, not a mistake."
Title: Re: Oxygen; too much, or not enough
Post by: yugamrap on March 21, 2010, 02:43:02 AM
I get such good aeration out of my cheap'n'easy Mixstir that I've never considered a more expensive/complicated method.
+1  I use my Mix-Stir as I run the wort to the fermenting bucket from the kettle.
Title: Re: Oxygen; too much, or not enough
Post by: beercheer4me on March 29, 2010, 06:25:37 PM
I am new and been reading alot on this forum ,,,,
I got a wine de-gaser  stir stix on a drill for 20 seconds
I guess it works, 
Title: Re: Oxygen; too much, or not enough
Post by: jjflash on April 08, 2010, 10:33:01 PM
Everyone always tells posters to aerate enough. So how much O2 is enough without using too much :?:

Per "Handbook of Brewing", 1ppm per degree Plato is the professional industry standard.
Impossible to measure this without a high quality oxygen saturation meter.
When people give you the advice for "X" minutes they are taking a wild guess.
Oxygen / yeast pitching rate are intimately correlated.
Some suggest underpitch and over oxygenate.
Others overpitch and under oxygenate.
It is always a balancing act.
Luckily, normal gravity worts are very forgiving of mistakes with oxygen.

Title: Re: Oxygen; too much, or not enough
Post by: tygo on April 08, 2010, 10:53:24 PM

Luckily, normal gravity worts are very forgiving of mistakes with oxygen.

What about very high gravity worts?  Planning on doing a 1.118 brew soon and have been debating how much oxygen to hit it with.  In my mental debate I think I'm currently at 30 seconds of pure O2 and then shake the hell out of it.
Title: Re: Oxygen; too much, or not enough
Post by: dhacker on April 09, 2010, 01:17:06 AM
Well . . there are those of the mind set that you can knock the oxygen OUT of solution by churning the wort too much after oxygenation. I know some individuals (specifically making starters on stir plates) that give the wort a blast of O2 and let it sit for several hours before spooling up the stir bar.
Title: Re: Oxygen; too much, or not enough
Post by: cojeep636 on April 09, 2010, 01:40:54 AM
I just thought i'd input, im relatively new to brewing, but thought i'd share some information from other sources that i've found.
I have a couple aquariums, and always thought that putting bubbles of air into the water would aid in the oxygen level in the water, but come to find out its a VERY minimal effect in comparison to circulating the top surface of liquid (in our case,  beer).

The idea is that the surface area of a group of bubbles is very little when compared to the top surface area of an aquarium, or again, in our case, a fermenter. The oxygen absorption, thus, takes place mostly on the top surface. So hopefully this can shine some light on the most effective methods of oxygenation.
Title: Re: Oxygen; too much, or not enough
Post by: jjflash on April 09, 2010, 02:22:00 AM
What about very high gravity worts? 

I would tag that one super high gravity wort.
Most unforgiving of mistakes.
When I brew that big I shoot for 18 - 20 ppm oxygen.
Remember it is a balancing act with yeast pitching rate.
I shoot for 0.75 - 1 million cells per degree Plato per milliliter on super high gravity wort.
Hit it with oxygen and let it sit quiet - oxygen easily comes out of solution.
Yeast propagate while oxygen is still present.
Yeast ferment when oxygen is depleted.
Title: Re: Oxygen; too much, or not enough
Post by: tygo on April 09, 2010, 02:38:07 AM
Ok, so no shaking and 1 min of bubbling O2 through the wort it is.
Title: Re: Oxygen; too much, or not enough
Post by: Kaiser on April 09, 2010, 04:09:00 AM
Yeast propagate while oxygen is still present.

They'll actually keep growing even once the oxygen is gone. What is happening is that the yeast is using the oxygen to build up their sterol reserves. These sterol reserves are depleted when the yeast is growing since in the absence of oxygen both the mother and the daughter cell get half. At some point growth will stop when the sterols in the yeasts are too low for further growth. But that happens quite a while after all the oxygen is consumed. High gravity fermentations need more O2 that regular fermentations since you don't want the yeast to deplete their sterol reserves too much. If that happens the cell walls get too weak to withstand the rather extreme alcohol concentrations.

In the presence of a lot of sugar, and any practical brewing wort has lots of sugar from the yeast's point of view, vey little to none of the oxygen is used metabolize sugars aerobically. Even in the presence of oxygen the yeast will ferment. This is called the Crabtree effect.

Kai