Inexpensive way to aerate wort

[oz11]

Using Pure CO2 is a tricky one, as it is all too easy to over saturate the wort with oxygen which will kill the yeast, however 30 seconds using a sintered stainless airstone immersed in the wort and stirring will achieve 10-12ppm with little effort. I have started oxygenating my yeast slurry prior to pitching, which is having very good results, but does require extra equipment.

CO2? :wha: :lol:

I have shamelessly ripped off Dunc's set up (from the other forum), and I blast with 02 at 1L/min for around 45s for 19L (with lid on). I'm hoping that's about right. I've not yet managed to completely knacker fermentation yet (though I s'pose there's always a first time).

Also, note this is much more important when using stronger worts and liquid yeasts, brewery slurry, etc than dried yeasts which really do not require you to go to these sort of lengths.

 

[Aleman]

Hi an air pump WON'T inject oxygen But it will drive of CO2! Even injecting oxygen won't do much more than that. This is a very common missaprehension!! Also the finer the bubbles the better!! Water can only hold so much O2 before it reaches saturation point, unless you increase the atmospheric pressure in the holding vessell. Also you can get plastic airstones (ebay)!! Or try looking for a sintered brass fuel/ air filter (got one running in my fish tank, works a treat)!! (might take some diy to fit tho)!

Only if there is CO2 in solution, and as we are talking about aerating wort before pitching there is no CO2 in solution. An Air pump (and Airstone - of whatever type) will add O2 to the wort up to the saturation point for it's current temperature, as we have (as all grain/extract brewers) boiled the wort and driven off any oxygen, it's important to add it back, and an air pump will help do this . . . unfortunately cheap ones do not provide enough 'uuummppppphhhh' to drive an air stone at the bottom of the bucket for any time. . . .but they do need to be used for 30 minutes or more to reach saturation

 

[Aleman]

CO2? :wha: :lol:

DOH!! . . . I should stick to using full names :lol: amended

 

[Swift Pint]

just out of interest, is it possible for us to measure the amount of O2 in our wort?
I bought the Salifert Oxygen test and have not yet had a chance to use it. But it did occur to me that the test is for fish tanks or ponds, and not sugary wort. Any idea whether these tests will work on wort or not?

Im guessing because the test is based on colours that its best to try on a pale wort.
Alternatively could I get a proxy by boiling plain water for an hour and then aerating it as if it were wort? or does sugar in solution impact O2 solubility? Am I going OTT? :wha:

 

[graysalchemy]

unfortunately cheap ones do not provide enough 'uuummppppphhhh' to drive an air stone at the bottom of the bucket for any time. . . .but they do need to be used for 30 minutes or more to reach saturation

My work compressor because that would certainly have enough uuuuuuuuuuuuuuummmmmmmmmmmppppppppppppppphhhhhhhhhhhhh..........................................

Unfortunately the air is dirty with oil and water and I don't have a refrigeration dryer and filters. :evil: :evil:

Ah well back to the monkey spanker then. :lol: :lol:

 

[Swift Pint]

There were selling air compressors in Lidl a while back.... :whistle:

 

[graysalchemy]

Yes but unless you have a dryer and filter on them they are no good as you will introduce oil and water into the wort. A dryer for my big hydrovane would probably cost as much as the compressor itself :lol: :lol:

 

[Swift Pint]

maybe the oil would be a good yeast nutrient.... :rofl:


I think the compressors were about £90 anyways.... they had all sort of random accessories to go with it.

 

[graysalchemy]

The air will not be clean, fine for a pnuematic stapler or spray gun but not to put in your beer IMHO.

 

[Mork]

So many contradicting ideas... who's right? Use a pump, use a plaster mixer, use pure Oxygen! I don't know what the answer is now! I thought I had done my research well enough through web searches... but now I'm just totally confused. Wish there was a definitive answer!

 

[oz11]

Like most things in brewing there's more than one way to skin a cat. Not right or wrong, just different. Consider the options, your budget, diy skills and take your pick!

I was after a closed run-off from boiler to FV, so dropping from a height into an open FV doesn't appeal.

 

[Swift Pint]

I used the electric hand whisk approach yesterday for the first time and I must say it worked rather well! :party:

 

[The Goatreich]

Is the sieve method I mentioned earlier not something I should be doing then? I get a ton of foam in the FV suggesting there's a lot of air in there.

 

[Swift Pint]

Goat, it sounds like a great way to aerate the wort. :thumb:
Just make extra sure the sieve is cleaned and sterilised first.

 

[The Goatreich]

Yeah, I've often thought that. Sieve's are a nightmare to keep clean though. I think I'll get my own one for brewing rather than use SWMBO's in the future.

 

[Swift Pint]

Yeah a brewing one that won't get tainted would be a good idea. I guess if you rinse it well straight after use then that will help too as you wont get any old wort drying on there.

 

[oz11]

I get a ton of foam in the FV suggesting there's a lot of air in there.

Problem is that air is less than 21% oxygen, and it's the oxygen the yeast need.

 

[Cononthebarber]

I never used to aerate at all before but then started using a steralised paint mixer and drill, I've noticed the fermentation starts off more vigourusly now and seems to finish quicker and reach a lower FG so I must be doing something right :lol:

 

[Aleman]

I get a ton of foam in the FV suggesting there's a lot of air in there.

Problem is that air is less than 21% oxygen, and it's the oxygen the yeast need.

However Yeast only need 8-12 ppm which is ( 8/10000 ) or 0.0008% . . . so 21% in the air is more than sufficient to eventually reach equilibrium at 8-12ppm . . .Using pure oxygen reaches that point much faster and with less foam (not so you would notice IME)

 

[BarnsleyBrewer]

I put mine in the back of the car and do a 5 mile round trip on the roads around here, the pot holes and speed ramps agitate it well!! :thumb:

BB