A Tip For Getting More Oxygen In...

[bear09]

Hi All,

The last 3 brews I have done have kicked off really well after 12-18 hours. I am putting this down to a better infusion of oxygen at pitching time.

I use glass fermenters.

When I am transferring the cooler wort into my fermenter I have an air pump and air stone running (thanks Ross). While transferring I constantly flick the hose back and fourth so the wort splashes and foams hard whilst pouring in. 3 brews ago I decided (I dont know why) to rest my fermenter on a blanket and every 30 seconds during the transfer I would rapidly swirl it. This combination of splashing the wort and swirling (and sloshing) it with the air stone running the whole time sees the wort full of 1000's of tiny air bubbles.

Once transfer is complete I continue the rapid swirling for another ten mins with the air stone going the whole time.

I have read the book 'Yeast'. I think (if I remember) that with an air stone the max O2 you can get is 8ppm. The optimal amount is 10-12ppm (I think). I think using this method above that I am giving the yeast the best possible chance of a good start and so far it really seems to have improved things.

Any one else use this method?

 

[ekul]

would it be beneficial to leave the air stone in there for 12 hours or so? So even though there isn't 10ppm in the wort at the start you are replenishing oxygen as it is used by the yeasties?

Recently i've been pouring in half the cube into the fermenter then shaking the shit out of the other half then adding it. I have noticed a slight imporvement. I've been looking at a venturi device for added oxygenation. Its just a t-piece in a siphon, need to go to bunnings.

 

[felten]

if you use the airstone for too long you will end up with a lot of foaming, and those are apparently head forming proteins being used up.

 

[Florian]

I have been using one of these diffusers with great success.



At pitching time I put the cube on it's side and remove the bung, replacing it with a freshly sanitised tap with the diffuser attached via a small peace of silicone hose.
Glad wrap over fermenter, hole through just big enough for the diffuser and open the tap, an the wort gets plenty of air exposure. If you have an air stone and pump as well, throw that into your fermenter before covering up with a new piece of glad wrap and give it another burst, and then another after 12-24 hours, or several times in between. I use an inline air filter as well.

With ambient air it's virtually impossible to over oxygenate your wort unless you do it later in the ferment than 12-24 hours.

However, once Ross gets the oxygen regulators back in stock I will be upgrading to pure oxygen, but that might still be awhile away.

 

[bear09]

If I could find the means to use pure oxygen I would jump on it. To date I cannot find an option that is worth it - everything with O2 on it seems to cost a fortune.

Interesting point above about over foaming potentially robbing you of head creating proteins... My beers are coming our rich and thick head wise so I dont think that that is giving me any issues.

Cheers.

 

[felten]

That was in response to trying it for 12hr straight. Head retention or not, would the amount of foam created for aerating that long cause a big mess?

 

[Online Brewing Supplies]

Even with a stone you will be very lucky to get 8 ppm more like 6 ppm, I know I have done it and I have the gear to test results . It was also an inline system running (25 min) from a compressor via filter into chilled wort so lot of bubbles but not much O2. With an aquarium pump at higher temps even less I expect .
I now use bottled O2 and achieve 12-14 ppm (tested) in 2-3 minutes. :icon_cheers:
GB

 

[Florian]

Head retention or not, would the amount of foam created for aerating that long cause a big mess?

It would definately create a huge mess if you leave the pump running, that's why it's best to give shorter bursts.
You don't have that problem with pure oxygen, as you only pump it in for a very short time, depending on your regulator.

 

[Kranky]

Even with a stone you will be very lucky to get 8 ppm more like 6 ppm, I know I have done it and I have the gear to test results . It was also an inline system running (25 min) from a compressor via filter into chilled wort so lot of bubbles but not much O2. With an aquarium pump at higher temps even less I expect .
I now use bottled O2 and achieve 12-14 ppm (tested) in 2-3 minutes. :icon_cheers:
GB

Where did you get the bottled 02?

 

[mfeighan]

your going to need to brew a heap of beer to be able to use all that o2 you have

Even with a stone you will be very lucky to get 8 ppm more like 6 ppm, I know I have done it and I have the gear to test results . It was also an inline system running (25 min) from a compressor via filter into chilled wort so lot of bubbles but not much O2. With an aquarium pump at higher temps even less I expect .
I now use bottled O2 and achieve 12-14 ppm (tested) in 2-3 minutes. :icon_cheers:
GB

 

[Online Brewing Supplies]

Where did you get the bottled 02?

BOC or similar.
GB

 

[notung]

I'd be interested to know whether BOC lease smaller bottles of o2 and what the prices were. I wish there were hardware store alternatives, as with the ozito co2 tanks etc. Aeration is going to be a goal of mine when I have go at barley wines and imperial stouts. I currently do what ekul does and shake the crap out of half the cube before it goes into the better bottle carboy.

 

[amiddler]

Even with a stone you will be very lucky to get 8 ppm more like 6 ppm, I know I have done it and I have the gear to test results . It was also an inline system running (25 min) from a compressor via filter into chilled wort so lot of bubbles but not much O2. With an aquarium pump at higher temps even less I expect .
I now use bottled O2 and achieve 12-14 ppm (tested) in 2-3 minutes. :icon_cheers:
GB

GB, How much extra O2 do you think one of those Spray Wort Aerators adds, if any? I wasn't prepared to go the whole hog to pure O2 and now use a wort aerator from plate chiller to fermenter then air pump and airstone for around 30mins with the fermenting getting going within 12-15 hours.

Drew

 

[Thirsty Boy]

You can beat the foam issue by not using a stone.

Stone to get initial oxygen into the wort - then just a plain line from the aquarium pump down to the bottom of the fermenter. A stream of larger bubbles will rise - now, not a lot of oxygen will diffuse from these larger bubbles into the wort, but some will & not a lot of foam will form either, so you can leave it running for hours and drip feed the yeast oxygen constantly, long after they would have used up all the dissolved O2 from even a pure oxygen system. Handily the bubbles will also set up a bit of a current in the wort, nicely diffusing the oxygen all around the fermenter. Bigger line equals bigger bubbles, equals less foam and seems to equal more "stirring" action.

Same thing works to constantly aerate a starter if you dont (or even if you do) have a stirplate. Lots of big bubbles, constant dribbling in of oxygen, constant circulation and agitation of the wort. Very nearly if not just as good as a striplate.

 

[ekul]

thats a great idea Thirsty! I think i have an old aquarium pump around somewhere, will give that a go.

 

[Online Brewing Supplies]

GB, How much extra O2 do you think one of those Spray Wort Aerators adds, if any? I wasn't prepared to go the whole hog to pure O2 and now use a wort aerator from plate chiller to fermenter then air pump and airstone for around 30mins with the fermenting getting going within 12-15 hours.

Drew

Only true indication can be given if tested with a DO meter.
GB

 

[Wolfy]

Even with a stone you will be very lucky to get 8 ppm more like 6 ppm, I know I have done it and I have the gear to test results

While I do not have the ability to test such things, I do expect that while this is true, and that shaking the fermentor as many of us do, will result in even less O2.
5 or 10 mins seems to be 'long enough' to shake it, but likely it needs much longer than that to get full saturation, it would be interesting to see if anyone has actually tested that.
The yeast book is vague in saying that it takes a deal of time and lots of back-work.

 

[Online Brewing Supplies]

While I do not have the ability to test such things, I do expect that while this is true, and that shaking the fermentor as many of us do, will result in even less O2.
5 or 10 mins seems to be 'long enough' to shake it, but likely it needs much longer than that to get full saturation, it would be interesting to see if anyone has actually tested that.
The yeast book is vague in saying that it takes a deal of time and lots of back-work.

If there is a brewer who lives local and wants to bring a sample over I will test it so we can all get some idea on how well each system works.
GB

 

[bnaujok]

While I do not have the ability to test such things, I do expect that while this is true, and that shaking the fermentor as many of us do, will result in even less O2.
5 or 10 mins seems to be 'long enough' to shake it, but likely it needs much longer than that to get full saturation, it would be interesting to see if anyone has actually tested that.
The yeast book is vague in saying that it takes a deal of time and lots of back-work.

Hmm.. the wyeast website says that 40 seconds of shaking the fermenter is all that's needed to get full saturation without pure O2 injection - faster than a pump & stone.

 

[Bribie G]

I now double drop most of my ales and get a good healthy ferment. Haven't tried it with lagers yet - I'd have to make sure the yeast pitching rate was good, or risk leaving too much in the first vessel after dropping.
I've just bought one of those diffusers that Florian posted, it is identical in width to a racking cane so easy to butt up against the end of a racking cane and slide a bit of hose over to join them. I'll put the cane into the tap of the upper fermenter and have the lower fermenter sitting at a height where the diffuser is a few cm inside the ferm so it doesn't go everywhere.