For those who brew less than 5 gallons, how long do you oxygenate your wort? I brew 2.5 gal batches and recently got an oxygen wand. I see the recommendations to oxygenate for 60 seconds to two minutes, but that seems geared toward a 5 gal batch. Should I halve that and go with 30 seconds to 60 seconds? Or is oxygenation not linear like that? I'm not super concerned about over-oxygenation, but I wouldn't mind getting double the uses out of the oxygen tank, if I can!
Oxygenating small batches
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Golddiggie
Well-Known Member
If you're using one of the red cylinders (propane bottle style), good luck. Those get used up fast due to nature of them as well as the 'regulator' you use. With no real way to tell what the flow rate is, you'll use more than needed more often than not. I went with a L/min regulator on a 20 cubic foot O2 tank years back. Still using it.
I would judge the flow rate by the OG and batch size. Typically a ~1.060 OG batch (7 gallons typically) would get 1.5L/min for 90-120 seconds (+/-). Bigger beers, or larger batch sizes, would get more.
Look for a CGA 540 to L/min O2 regulator and then go to your local welding gas supplier and get a bottle from them. You'll probably get hundreds of batches out of it.
I would judge the flow rate by the OG and batch size. Typically a ~1.060 OG batch (7 gallons typically) would get 1.5L/min for 90-120 seconds (+/-). Bigger beers, or larger batch sizes, would get more.
Look for a CGA 540 to L/min O2 regulator and then go to your local welding gas supplier and get a bottle from them. You'll probably get hundreds of batches out of it.
I think it depends on the height/width ratio of your wort inside the fermenter you're oxygenating. That column of wort, if shallow will dissolve less O2 than a deep one, as any bubbles that reach the surface won't oxygenate your wort anymore. When the way up is longer, more O2 can dissolve.
In that light, I use a flow rate of 1/4 l/m for 4 minutes in a 5.5 gallon batch in a standard brew bucket (6.5 gallon ale pail). I move/stir the wand around periodically, about every 30 seconds, to as new "corner."
So yes, for half a batch, oxygenate at about half the time or much better, half the rate (because the wort is likely shallower).
As @Golddiggie said, it's tricky to regulate the output on those little red tanks. They should be good for 20-some 5 gallon batches for 1 minute each, only cracking them open just enough to see a coating of bubbles emerging from the stone, and rising. Some surface foaming is normal, but when you see any rippling or bubbling you're wasted O2, so close the valve down a bit.
I've heard those valves on the mini red tanks can sometimes leak, so maybe best remove the valve between uses.
If you're a serious brewer and brew enough, get a real tank. 40 cf may last nearly a lifetime.
Buy a regulator for around $30. Mine goes down to 1/32 l/m, which I use for oxygenating yeast starters, or leftover wort in a gallon jug.
In that light, I use a flow rate of 1/4 l/m for 4 minutes in a 5.5 gallon batch in a standard brew bucket (6.5 gallon ale pail). I move/stir the wand around periodically, about every 30 seconds, to as new "corner."
So yes, for half a batch, oxygenate at about half the time or much better, half the rate (because the wort is likely shallower).
As @Golddiggie said, it's tricky to regulate the output on those little red tanks. They should be good for 20-some 5 gallon batches for 1 minute each, only cracking them open just enough to see a coating of bubbles emerging from the stone, and rising. Some surface foaming is normal, but when you see any rippling or bubbling you're wasted O2, so close the valve down a bit.
I've heard those valves on the mini red tanks can sometimes leak, so maybe best remove the valve between uses.
If you're a serious brewer and brew enough, get a real tank. 40 cf may last nearly a lifetime.
Buy a regulator for around $30. Mine goes down to 1/32 l/m, which I use for oxygenating yeast starters, or leftover wort in a gallon jug.
fwiw, I picked up a 20cf O2 cylinder in 2008, and have swapped it 4 times (last swap was just a couple weeks ago) while averaging 180 gallons per year production. So, 3.something years per fill, which makes sense, as I use .5 lpm for 4 minutes per carboy plus I charge up my starters with O2, and there's a little under 600 liters per fill...
Cheers!
Cheers!
OP
OP
palmtrees
Well-Known Member
Thanks all, that's very helpful. I'm indeed using a little gold regulator with the red tank. That's very good to know that I shouldn't go full bore with the flow. Since I just bought it, I'll stick with it for a bit before getting a more exact one, though it does seem like a much better option in the long run. I only brew every two weeks, so I bet the big tank would last me a lifetime!
Golddiggie
Well-Known Member
FYI, for starters, I just use the stirplate with one of the foam stoppers (lets air exchange, but keeps the nasties OUT) in the flask. Zero issues and lets me save the O2 bottle for beer.
I will be using the SS Brew Tech inline oxygen infuser for the first time next batch. It will be going at the wort out side of my plate chiller. I might use more O2 this way, but last batch (13+ gallons into fermenter for 12 gallons out) chilled from whirlpool rest to about 62F (in the fermenter after all was in) in about 9 minutes. We won't be doing 12 gallon batches much, if at all, moving forward. Most of the time we do 6 gallon batches (in keg volume) or a 9 gallon batch when it's the English IPA recipe. Even adding more since I'm switching to conicals, I don't expect to have all that long of a chill time.
No matter HOW you get O2 into your wort, your yeast will LOVE you for it. They'll show that by getting to work faster, doing it better and giving you joy in your glass. Once I started doing the O2 via the wand and stone method, I never looked back.
I will be using the SS Brew Tech inline oxygen infuser for the first time next batch. It will be going at the wort out side of my plate chiller. I might use more O2 this way, but last batch (13+ gallons into fermenter for 12 gallons out) chilled from whirlpool rest to about 62F (in the fermenter after all was in) in about 9 minutes. We won't be doing 12 gallon batches much, if at all, moving forward. Most of the time we do 6 gallon batches (in keg volume) or a 9 gallon batch when it's the English IPA recipe. Even adding more since I'm switching to conicals, I don't expect to have all that long of a chill time.
No matter HOW you get O2 into your wort, your yeast will LOVE you for it. They'll show that by getting to work faster, doing it better and giving you joy in your glass. Once I started doing the O2 via the wand and stone method, I never looked back.
fwiw, I also use a foam stopper on my 5 liter e-flask on one of my stir tables, but I still give each starter a jump start with straight O2.
I don't see a point in "saving" anything for anything, ever, if it's good. I'll just get more!
Cheers!
I don't see a point in "saving" anything for anything, ever, if it's good. I'll just get more!
Cheers!
OP
OP
palmtrees
Well-Known Member
I'm hoping I see some improvements with oxygenation. After getting a handle on temp control last year, I'm focusing more on yeast health now. I've been doing starters but still feel like I have room to improve and make the yeast happier. So far, I've dosed one batch with the oxygen, and the US-05 I pitched took off faster than I've ever seen it go before. Hoping this helps stave off some FG issues and residual sweetness I've been noticing lately.
Golddiggie
Well-Known Member
Try adding yeast nutrient to your wort (last 15 or 20 minutes of the boil) and watch it take off even better/faster. I add some when I drop in the whirlfloc tablet(s).
IMO/IME, pitching the right amount (or as close as possible) of yeast cells into the wort, plus adding pure O2, along with nutrients does wonders. The pure O2 means the yeast WILL have enough O2 to make healthy/strong cell walls during the initial replication stage of fermentation. Starters get your initial yeast population closer to where it should be for the recipe. Combine the two, along with some additional nutrients for the yeast and you'll have strong yeast/fermentation with reduced lag times.
FYI, I use temperature of the batch to tell me when the yeast are done. Basically, when the beer reaches ambient temperatures, I know they're done. That's with ale yeast at least. Even more so since I watch the temperature rise post pitch, plateau, and then drop. Last batch was done fermenting in about a week (not more than a week, but possibly less). Which is pretty common for my moderate OG batches/recipes. Bigger beers take longer. Those also need more O2 in the wort.
This is a similar regulator to what I have. https://www.amazon.com/CGA-540-Style-Oxygen-Regulator/dp/B006GERK0M
Since I have yet to go above 2L/min, I don't mind that 8L/min is my max. For $45 it's well worth getting. I am glad I made the adapter to go from the connection it comes with (threaded) to 1/4 NPT so that I could fit a ball lock gas post. Especially since I need the ability to change between the wand and the inline infusion system. Those two use very different size tubings. Wand is 3/16", inline system has a 3/8" barb. Now I'll just put a gas QD on either one and have no concerns.
IMO/IME, pitching the right amount (or as close as possible) of yeast cells into the wort, plus adding pure O2, along with nutrients does wonders. The pure O2 means the yeast WILL have enough O2 to make healthy/strong cell walls during the initial replication stage of fermentation. Starters get your initial yeast population closer to where it should be for the recipe. Combine the two, along with some additional nutrients for the yeast and you'll have strong yeast/fermentation with reduced lag times.
FYI, I use temperature of the batch to tell me when the yeast are done. Basically, when the beer reaches ambient temperatures, I know they're done. That's with ale yeast at least. Even more so since I watch the temperature rise post pitch, plateau, and then drop. Last batch was done fermenting in about a week (not more than a week, but possibly less). Which is pretty common for my moderate OG batches/recipes. Bigger beers take longer. Those also need more O2 in the wort.
This is a similar regulator to what I have. https://www.amazon.com/CGA-540-Style-Oxygen-Regulator/dp/B006GERK0M
Since I have yet to go above 2L/min, I don't mind that 8L/min is my max. For $45 it's well worth getting. I am glad I made the adapter to go from the connection it comes with (threaded) to 1/4 NPT so that I could fit a ball lock gas post. Especially since I need the ability to change between the wand and the inline infusion system. Those two use very different size tubings. Wand is 3/16", inline system has a 3/8" barb. Now I'll just put a gas QD on either one and have no concerns.
