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Oxygenating Wort
I read on the Danstar website that when using dry yeast oxygenation the wort is not required. It is only necessary for liquid yeasts. I had never heard that before and was wondering what your thoughts on the subject were.
Also I was thinking the other day about how to get more oxygen dissolved in the wort without having to resort to an oxygen injection system. Other than the tried and true "grab the carboy and shake the livin' bejesus out of it" method.
What about using hydrogen peroxide? The catalase from the yeast would break the H2O2 down into water and O2, which would oxygenate the wort. From what I have read it doesn't seem to hurt the yeast, it's one of their natural processes. So do you think this would work or have I gone off the deep end?
I just pour my wort into three gallons of cold water in my bottling bucket (partial boil) and then from the bottling bucket I funnel it into the carboy, the pouring through the funnel seems to churn it up enough; I've always been a skeptic to picking up a full glass carboy and shaking it, the potential for dropping it seems to high for me. I understand that on the heavier brews it's recomended to really oxygenate, but it also seems that some people take this a little to seriously/far. I haven't had a problem with my brews using this method, granted I haven't been doing beer that long. Does more oxygenation produce a lower final gravity? More experienced brewers may tell me I'm bonkers but you can't argue with success and I haven't had a batch go bad yet...the operative word is yet.
Correct me if I'm wrong but isn't oxygenating primarilly to give the yeast a head start on potential bacteria? I would think if you sanitize well enough the yeast has a pretty good chance to get ahead of any bacteria, once it's going and fills the carboy with CO2 the dangerous bacteria aren't able to live in a CO2 rich environment, the danger at that point would really be the introduction of foreign natural yeasts floating arround in the air, and even that chance seems slim with a carboy (small opening compared to a fermenting bucket).
On the subject of peroxide I suppose it could work but have you ever taken a sip of peroxide? Yuck. I'd just think you'd be adding a gross flavor to the brew. You could get a fish tank pump with one of those stones that makes the really little bubbles, let that go for a few minuets.
urchin - The way I understand it boiling the wort removes the oxygen from it. When you do a partial boil and add it to cold water you would have more oxygen in your wort than doing a full boil. All I have done to this point is shake the carboy to oxygenate as well as I could, but then all I have used to this point is dry yeast and according to Danstar oxygenation isn't required for dry yeast. I agree with you, for higher gravity beers oxygenation is probably more important but I am not sure how important it is for the average beers we brew.
The way I understand it, yeast need oxygen to reproduce. The more dissolved oxygen in the wort the more reproduction you get so you have more yeast to get down to the serious business of producing alcohol. 
The higher the yeast count the faster they can overwhelm any stray bacteria in the wort. A lot of the nastiest bacteria out there are anaerobic (e coli, staph, botulism). Not that we will end up with those in our brews, but an environment that is conducive to yeast is also extremely conducive to bacteria.
I don't think peroxide has a flavor any different from water. What you taste when you take a sip of it is the gunk it removes from the inside of your mouth(we have catalase too). I was just wondering if it might work. An aeration stone and an air pump might be a better solution but it is something else to buy, and another piece of equipment to sanitize. Peroxide is cheap, and for a bigger beer it might be a cheap and easy solution. Or then again, maybe I have gone off the deep end. 
ruralbrew wrote:
The way I understand it, yeast need oxygen to reproduce. The more dissolved oxygen in the wort the more reproduction you get so you have more yeast to get down to the serious business of producing alcohol.
The higher the yeast count the faster they can overwhelm any stray bacteria in the wort. A lot of the nastiest bacteria out there are anaerobic (e coli, staph, botulism). Not that we will end up with those in our brews, but an environment that is conducive to yeast is also extremely conducive to bacteria.
Very well put.
The numbers may not be exact, but basically shaking the carboy (vigorously for 5 minutes) will give you about 10% POTENTIAL absorption. Using an aquarium pump through a stone may double that, giving up to 20% potential absorption. Remember atmospheric air is only 19% or so (?) O2, so the wort maybe absorbing air, but not pure O2. Direct injecting O2 through a stone can give 80-100% potential absorption. And it is simple, crack the valve for 45 seconds, and done.
Oxygen is extremely important, and necessary for all beers and yeasts. It is like wyeast claiming you do not need a starter with a smackpack, maybe you dont NEED one, but it will make a better beer with a larger count of viable yeast if you do. As homebrewers we all WAY underpitch the count of viable cells. We may think we are adding quite a bit, or even overpitching, however there is a difference between cell count and VIABLE cell count in your slurry. The pros have labs and can figure out actual count and adjust depending on the gravity of wort. The higher the gravity, and lower the ferm temp, the more these counts are necessary on a more exponential than linear increase, which is why whenever these topics are brought up, they are usually correct, however low gravity beers still require these fundamentals.
So I say if it helps your fermentation to be quick starting and vigorous, do it.
last things I need, a place to control my fermentation temps, and an Oxygen set up.
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