Greetings All - for my entire 8 years of home brewing I have used an aquarium pump to oxygenate my wort. Now, I decided to use pure oxygen, but have absolutely no idea how to use it.
I bought the regulator and have fitted it to my filter, wand and stone. So I believe, mechanically, I’m ready to go.
So, now what? How long do I aerate? Should I move the stone around the fermentor or set it and leave it? And, at what flow rate (if there is such a thing) do I dial in the regulator?
I just put in the stone, turn on the O2, and watch the bubbles as I move it around for 30 seconds or so… I don’t time it… I just “count”. When one area looks all bubbly, I move it to another spot.
I do much the same as Allen above, with the stone mounted on the end of a wand, tied with tubing to a kegland.com flow meter tie-wrapped to a Bernz-O-Matic red oxygen bottle, set at between 0.2 and 0.5 liters/minute, for 30-45 seconds.
Both good suggestions. Thanks!
I guess my concern is over-oxygenating - if that’ even possible???
Just to throw another monkey wrench in the works, I don’t use pure O2 to aerate wort. I have a curved piece of copper tubing that has a bunch of holes drilled in it at an angle. I put this on the end of my transfer hose (with the angled holes facing down) when filling the fermenter and it sucks in air while the beer is going through it (much like Saccromyces does). It’s cheap to make, negates the cost of having a bottle/tank of O2 around, and works just as well for me. My lag times are relatively short 5-6 hours.
I used to do O2 for about a minute. Now I just circulate my wort in the SS conical while the cooling coil is doing it’s job dropping wort to pitch temp. Faster cooling while aerating. Two birds, one stone.
For all practical purposes, probably not.
I’ve always oxygenated 1 min with ale strains, 2 min for lagers, high-gravity worts, or O2-hungry ale strains. Am I doing it correctly? Well, I can’t measure how much O2 is dissolving, so I’ve just let how the beers turn out tell me if I’m on track. After hundreds of batches doing it this way, yes, I am doing it correctly.
You just want a fine mist of bubbles coming from the stone. You’re not trying to make the wort look like a hot tub. Any bubbles reaching the surface is wasted, undissolved O2. Gently move the wand around for maximum mixing.
With my last O2 tank (the small red welding kind), I got 155 minutes of oxygenation. That’s a lot of batches. YMMV but those tanks last a long time if you don’t waste the O2.
Somewhere in the fog of my memory I recall reading that too much O2 can be toxic to yeast.
Too much of anything is toxic. But “too much” means different amounts for different molecules and for different organisms. Over-oxygenating by a minute or two will have no impact. Over-oxygenating by 20 minutes is probably bad.
Aerating the wort before it has reached the ferment temp is generally a bad idea. Ideally it should only be done after pitch or very close to pitching.
I’m not sure that we can achieve O2 toxicity, but I recall Jamil saying he thought that excessive oxygenation results in Fusel production. I’m fairly reserved when oxygenating for that reason.
For what its worth, I just let the cooled wort drop from the top of my conical when transferring. When looking into the top of FV the wort is all nice and frothy. I can’t tell you how much O2 is added this way but it has been working for me. Short lag times even when using re-pitched yeast. I used to oxygenate and still do on big beers but not so much anymore on others.
Yes by causing accelerated yeast growth.
I think I may have killed a yeast starter with pure o2 one time. Course, I don’t know for sure. It was dead AF though
FWIW, just barely turn the regulator on enough to get oxygen to flow from the stone. The first couple of times I tried it (and that was 20 years ago), I cranked the regulator open all the way…and found I used an entire small oxygen bottle on two batches. Whoops.
+1 – I can get 6-10 batches off one tank
I have a 5# bottle, regulator and a 0.5 micron stone, set the regulator at 0.5 lpm and give it 60 seconds. At that rate IIRC I got a couple hundred batches out of the 1st bottle. I also have read somewhere [maybe Palmer?] that pure O2 can kill yeast, at least under the wrong circumstances. As with yeast nutrient I figure it’s cheap insurance.
I get about 110 batches off one tank. Obviously we’re oxygenating very differently. I wish it was feasible to test how much oxygen is being added…
I agree with this. Otherwise the oxygen is doing something else in the wort, regardless of what that something else might be.
We’re now in the realm of (possible) brewing mythology. “I heard this somewhere…I read this somewhere…I recall this…I recall that…from this or that brewer/homebrewer…” etc. Anecdotes passed down from “experts.”
Is there credible, peer-reviewed, real-world-applicable literature on this, from actual brewing scientists, re: brewing strains of S. cerevisiae specifically? Talk to me, Dr. Bamforth.
I’ll add my own anecdote: I’ve likely over-oxygenated quite a bit. I now even oxygenate my 1-liter starters with the O2 tank and wand. Never had an issue with yeast performance or, most importantly, the final product. But the plural of anecdote is not “data”. Reactive Oxygen Species (ROS) is definitely a thing for all aerobes on this planet. But I’m not sure they have affected my beer yet.
If too much oxygen (within reason; see my previous comment) is toxic to brewing yeast, I feel like I would know by now. Could this be yet another brewing myth?
For low gravity beer less than 1.060 simple aeration provides ample oxygenation.
For high gravity beer I use 1 PPM per degree Plato oxygen.
Without a good DO (dissolved oxygen) meter it is impossible to tell how much oxygen you are putting in.
As a friend once told me, it is like turning on the shower and telling me to turn it off at 16 gallons - near impossible.
For most of us we used trial and error method - 10 minutes and beer okay, next time lets try 5 minutes and see if still good, then 2 minutes…
I have use high quality DO meter for years.
The amount of oxygen actually getting into the wort I discovered can be quite variable depending upon technique.
The good news is, early on I also discovered oxygen readily diffuses out of the wort.
So if you shoot too in much oxygen, over oxygenated, it just comes right out of solution within a short time.