Aeration of wort before pitching yeast

[Laripu]

Yeast needs oxygen to thrive before it goes anaerobic, and while I've known this for 20 years, up to now I've been aerating wort by just shaking the carboy to mix air in. As I age this gets harder and I've decided it's time to go to a technological method.

I don't want an oxygen tank around the house, so I think that a diffusion stone, in-line air filter, and aquarium pump is my way forward. I was thinking of buying something like this or similar.

You guys often have good ideas, and I'd be interested in hearing them. How do you aerate your wort prior to pitching? What do you think of that system or other systems?

[art.b]

i use a plastic brewing paddle, in a battery drill keep the revs down and you will be fine...

[Laripu]

i use a plastic brewing paddle, in a battery drill keep the revs down and you will be fine...

Yes, that will work best if you do it to the surface of the wort as it's being siphoned into the FV, moving the paddle up as the wort comes up. It's more difficult for me because I ferment in glass.

Good idea for plastic cylindrical FVs, though.

[stu-le-brew]

I was thinking of buying something like this or similar.

I have one of those but haven't used it for years - to get oxygen into the wort I simply flow the wort from the copper and allow it to fall the from the top of the fermenter - I have never had a problem with the yeast.
If I remember correctly when I did use the air stone it kept floating up to the top and was not working to well at airating the wort - so I dumped that idea and went for a simpler way.

[Laripu]

I was thinking of buying something like this or similar.

I have one of those but haven't used it for years - to get oxygen into the wort I simply flow the wort from the copper and allow it to fall the from the top of the fermenter - I have never had a problem with the yeast.
If I remember correctly when I did use the air stone it kept floating up to the top and was not working to well at airating the wort - so I dumped that idea and went for a simpler way.

Stone floating to the top - good point. These people have solved that with this approach.

This is good - I'm learning about some of the problems with aeration, and how to get around them.

About allowing the wort to simply fall into the fermentor - I've done that, including moving the hose around to make the wort splash. From what I've read, that yields about 3 ppm max (just like shaking the fermentor), and the optimum for yeast is 8 to 10 ppm. The result of lower oxygen is slightly higher terminal gravity - not that big a problem - and slightly higher ester level. Not a problem for ales or Belgian styles, but I also brew lagers which I'd like to be as clean as possible.

I've heard that there has been some research on using very small quantities of olive oil for very fast start to fermentation, (but not as a substitute for aeration). (See http://brewcrazy.com/brewing-beer-with- ... rticle.htm and http://www.brewcrazy.com/hull-olive-oil-thesis.pdf). I'm not sure I believe it, but I might try it anyway one day.

Please, keep the challenging ideas coming.

[gregorach]

I use bottled oxygen - a small disposable welding cylinder isn't a big deal. i wouldn't want a full-sized technical cylinder around the house either. I'd never get one up the stairs, for one thing...

[liquidman]

I've just gotten to the bit about using olive oil instead of aerating the wort in the yeast book by Mr. White, very interesting... (Please picture a bald man, sitting in a leather chair, stroking a white haired cat)

A

[jmc]

I use bottled oxygen - a small disposable welding cylinder isn't a big deal. i wouldn't want a full-sized technical cylinder around the house either. I'd never get one up the stairs, for one thing...

Hi gregorach

Is this the sort of disposable oxygen canister you mean?
Oxyturbo 480300 Oxygen Gas cylinder


If so what sort of regulator / kit do you need to oxygenate wort using this?

I'm tempted to use this but I'm not convinced yet its worth the extra time and expense?
TIA John

[gregorach]

Yep, that's exactly the very thing. You need this regulator, a stainless steel airstone, and some tubing to connect it together. I think it's also well worth getting some kind of flowmeter (I use this one) so you know how much O2 you're injecting.

As to whether you it's worth the time and expense... I couldn't say. I feel I'm getting better and more consistent results, but it's not a massively noticeable improvement. However, the time / expense / hassle isn't that much more than that involved with an aquarium air pump (and in some ways less - no need to replace filters for one thing), so I would say if you're going down that sort of route, you might as well do it properly.

[jmc]

Hi gregorach

Thanks for the detailed info, much appreciated.

Bit too pricey an option for me at the moment

ATB
John

[CRoark]

Yep, that's exactly the very thing. You need this regulator, a stainless steel airstone, and some tubing to connect it together. I think it's also well worth getting some kind of flowmeter (I use this one) so you know how much O2 you're injecting.

As to whether you it's worth the time and expense... I couldn't say. I feel I'm getting better and more consistent results, but it's not a massively noticeable improvement. However, the time / expense / hassle isn't that much more than that involved with an aquarium air pump (and in some ways less - no need to replace filters for one thing), so I would say if you're going down that sort of route, you might as well do it properly.

About how many brews do you get out of one canister? And do you just order online and they ship them to you with no problems?
thanks..

[darkonnis]

I use a little air pump with a sterile filter and a ceramic stone, used it on my latest big batch and trying it with my trial brews and i have to say (as clive said to me) once you try oxygen... you won't want to go back. It smooths out a lot of the roughness and a lot of what i can only guess to be estery type flavours.
I just turn the wee thing on, dump the stone in and come back after 20 minutes, job done, nothing highly technical. Can't remember why I decided 20 minutes... but I do remember reading something that reckons you start hitting the sat point for DO not long after this.

Duncs set up looks more flash and maybe more manageable but mine cost me £20 and it is definitely fit for purpose.

[gregorach]

About how many brews do you get out of one canister?

I don't know, I haven't finished one yet. Haven't been brewing much the last couple of years though...

And do you just order online and they ship them to you with no problems?

Yup.

[gregorach]

Doing a bit of digging around, it looks like these cylinders contain 136g of O2, which by my calculations is 17 moles, so assuming 22.4 L/mol at STP, we're looking at 380L of O2 in there. I typically use it at a rate of 1 L/min for 60 seconds of actual oxygenation, plus some extra both before and after immersion, so lets say 2L per batch - in which case, there's enough O2 in there for 190 batches. Seems suspiciously high to me, but I can't see any obvious errors in the maths... Whether you can actually get all of the contents out of the cylinder at that flow rate is another question. Of course, you can always increase the time to compensate for reduced flow rate.

[Nofolkandchance]

Leccy drill and a paddle