How long to aerate with diffusion stone & aquarium pump?

[Algernon]

Fantastic info - Thanks Shane.

So in short, I can get super lazy now I am doing AG but pitching dried yeast.

What are the advantages to pitching liquid yeast then?

Also, when re-hydrating dried yeast, I hear different things all the time. Some say do it with a pinch of DME in the water, some say NO! Some say there's no need at all and just to sprinkle it on top of the wort. There's even different views on stirring it in vs leaving it to float...

All in all, does it really make a difference?

Thanks again for the info

Al

 

[Vossy1]

If you intend to brew specialist high gravity ales old barley wines, imperial stouts etc you may wish to consider Wyest advice

Oxygenation
As wort gravity increases, solubility of oxygen decreases. It is very important to compensate for the decrease in solubility by oxygenating more aggressively. When brewing high gravity beers, it is best to oxygenate with pure oxygen through a scintered stone.

or White and Zainasheff's, page 93 of Yeast

If it is a very high gravity wort, more than 1.092, you must aerate with pure oxygen as air will not provide a high enough level of oxygen

The rest is beyond me, or should I say beyond that which I need to know at this moment in time, and as Shane said

I would not bother using pure oxygen at home its a waste of money

..that's true in 99.9%* of domestic use.
*figuratively speaking

 

[oz11]

From my experience of using oxygen vs. not using it I get a more reliable fermentation that is quicker and reaches a lower FG. That said I brew in a 60's garage with all sort of unpleasant stuff in it and so have a closed run-off to the FV (so as the FV isn't open to any spores, etc that are knocking around) and so it does not get aerated during the transfer. I use a flow meter to be able to measure the amount of oxygen being added. YMMV.

 

[unclepumble]

From my experience of using oxygen vs. not using it I get a more reliable fermentation that is quicker and reaches a lower FG. That said I brew in a 60's garage with all sort of unpleasant stuff in it and so have a closed run-off to the FV (so as the FV isn't open to any spores, etc that are knocking around) and so it does not get aerated during the transfer. I use a flow meter to be able to measure the amount of oxygen being added. YMMV.

If you can measure the amount your adding acurately each time and the amount is repeatable, controlled and gives good results, by all means use oxygen, however you will need a certain amount of trial and error to find the optimum amount to add.

If you intend to brew specialist high gravity ales old barley wines, imperial stouts etc you may wish to consider Wyest advice

You still don't need to use oxygen, with high gravity beers aerate as usual then do again around 6-8Hrs after pitching but ensure there is no sign of fermentation starting if doing so. Yeast use up oxygen very quickly usually within 30 minutes of exposure.

Fantastic info - Thanks Shane.

So in short, I can get super lazy now I am doing AG but pitching dried yeast.

What are the advantages to pitching liquid yeast then?

Also, when re-hydrating dried yeast, I hear different things all the time. Some say do it with a pinch of DME in the water, some say NO! Some say there's no need at all and just to sprinkle it on top of the wort. There's even different views on stirring it in vs leaving it to float...

All in all, does it really make a difference?

Thanks again for the info

Al

In My experience Dried yeast is harder work than wet yeast, if done properly, as you have to hyrate with boiled water that had to be cooled to 35 deg C then left and cooled further b4 pitching etc etc IT IS A FAFF

Liquid Yeast gives better results IMHO the beer produced is usually better

When Rehydrating just use water nothing else, if you sprinkle, you risk under pitching as the yeast regenerate better with warmth £0-35Deg C water than they do with a cold wort at 18-20Deg C, you will find many of the cells die when just sprinkled.

All in all, does it really make a difference?

Without any doubt YES! The Yeast used accounts for 85% of The Flavour, Mouthfeel and aroma of the finished beer, therefore correct yeats choice and husbandry is critical to getting the best beer you can make!

Cheers

Shane

 

[Algernon]

Thanks Shane. I shall take much better care of my little yeasties than I have done so far. I'm always good to them once they have done their work, I rinse them away with warm water and wish them all the best. Maybe I shouldn't put the poor little buggers through "trial by osmotic and thermal shock" when I first use them.
My problem is that I am only just starting my AG process and don't have a tap or a cooler on my 70l shiny pot. Makes it hard to aerate my wort without leaving it wide open to get infected.
Once I have a tap and hop filter on my boiler I should be able to cool it and drop it into the FV from on high, which I am lead to believe will generally aerate all but the most hungry of imperial beers. Would I be right in thinking if you drop enough yeast in you need to aerate less anyway, since the oxygen is really just for the growth phase? So a recycled yeast cake from a secondary fermantation (less trub) might be the way to go for a big heavy beer?