Wort Aeration How Long

[RabMaxwell]

Hello all going to brew tomorrow & going to use my mini compressor set-up to my stainless airstone plugged into a timmer then go to bed.I will have it cutting on & off so it doesn't build up to much foam.I wan't to give the yeast a good start with plenty oxygen but how many hours into the fermentation should i go before stopping. Cheers

[Whorst]

I use pure oxygen and I go for 45-60 seconds. I oxygenate before I pitch the yeast. If you're not using pure oxygen, 15 minutes would be adequate.

[hoppingMad]

I would like to know the benifit of this technique. I looked into it a while back and decided it was too expensive and fiddly. So I did some reading on aeration and ended up buying a paint stirrer for my electric drill. I now chill the wort first, then aerate with the paint stirrer for about 2 minutes, then pitch the yeast.
I used the overall fermentation time to help me guage whether or not my aeration of the wort was sufficient.
Lagers chilled to 9C then aerated, take 12-14 days to attenuate fully at 9 degrees C, ( including a D rest for the last 2 days) which seems about right to me. I have not heard anyone say their 9 C fermentations take less time than this.
But I'm all about improving my lager fermentaions, and would switch in a minute if I thought O2 pump is a better idea.
Hopp.

[RabMaxwell]

I wouldn't like to say how long but can't you use anti-foam ? (you will make lots of foam otherwise).

I will be using antifoam Chris i have just been wondering about the benefits of giving a couple more blasts of air a few hours into fermentation.I have never been able to crack safale 04 often getting higher FG's than wanted.I have been told that it's a yeast that's greedy for o2 so want to give it a few extra blasts.But not to sure how far into the fermentation you can go before the aeration becomes detrimental.

[Aleman]

Up to about 18 hours after pitching

It does depend on the yeast though, and the quantities you pitch. The 'ideal' time to stop is when the yeast just start to form little islands on top of the brew . . . . . Of course that is difficult to see if you are aerating. . . . Personally I go for O2 at 2L/Min during transfer of the cold wort to the FV, which does the job for me . . . . although once the O2 Supply has dried up then I will be down to air, and will probably go for 10L per min of Air during wort transfer and then 15 minutes at 12 Hours after pitching for big beers

[RabMaxwell]

Cheers all. Aleman how do you calculate for 10 litres per min

[Aleman]

My O2 reg has settings for 2, 4, 6, 8, and 10L/Min, I will probably have to get some sort of flowmeter for the air compressor that tells me the same thing

[edit1now]

I have one of these on my MIG welding rig, though mine only does 0-10 l/min.

Here's another picture in case the eBay one disappears.

[RabMaxwell]

I have one of these on my MIG welding rig, though mine only does 0-10 l/min.

Here's another picture in case the eBay one disappears.

That looks ideal thats if i can fit it to my air brush compressor looks possible

[edit1now]

You might need some adaptors from the regulator-type fitting on the flowmeter to the airbrush compressor, which is probably 1/8" BSP...

[RabMaxwell]

I wonder if i could run it directly of the air brush compressor or if i would need to buy a air tank for the compressor then run the air flow meter of the tank ?

[edit1now]

What kind of compressor is it? The only bit I would worry about is whether the air is oily or not. Diaphragm compressors (like an aquarium pump but bigger) always give clean air. Reciprocating compressors (like the big ones in garages with an obvious cylinder head) give oily air, which needs to go through an oil trap or filter. Whichever sort you have, you then want a HEPA filter between the air source and the aeration stone, so the air getting to the wort is more-or-less sterile, otherwise you might get lambic. You should only need a tank for the compressor if you're not allowed to make compressor noises in the middle of the night