How long to aerate with diffusion stone & aquarium pump?

[Loetz]

I got my stone from Hop and Grape.

 

[dennisdk2000]

Haven't got mine yet - will be getting it from Hop & Grape.

Dennis

 

[evanvine]

£9.60 at The Home Brew Shop
Apparently they need 15psi to drive them.
Is this true??

 

[dennisdk2000]

£9.60 at The Home Brew Shop
Apparently they need 15psi to drive them.
Is this true??

I can't say for sure - the one I'm getting is a 2.0 micron, rather than the 0.5 micron shown in the link.

From MoreBeer:

"The 2 Micron size is more commonly used for aeration or oxygenation pre fermentation, but can be used to carbonate beer. If you wish to use an aquarium style Aeration Pump to pump air through this stone we recommend a "deep water" type for aquariums, as these will have the necessary PSI to force the air through the stone and into the wort."

Also from MoreBeer:

"The .5 Micron stone is more commonly used for carbonation. However it can be used pre-fermentation with an O2 tank and regulator for oxygenation. Not the ideal choice if you want to aerate with an oxygen pump (aquarium pump) - use KEG590 for aeration."

Dennis

 

[evanvine]

Nothing's ever simple is it Dennis!

 

[Vossy1]

Apparently they need 15psi to drive them.
Is this true??

I have the 2 micron stones and they do take quite a wallop to get the air through, but I don't think it's anywhere near 15PSI. I think I used this pump originally and you had to be careful. Start the pump before the stone got wet...no probs, try and start it after...no way..or a great deal of difficulty.

I have my mini compressor handy so will give the airstone a go in a min and report back :thumb:

EDIT....no filter or non return valve (aquarium spring type) fitted and the air stone works at sub 2PSI, it actually reads less than half of 2! Will check with filter and nrv fitted next.

EDIT 2...same result with nrv and filter fitted :thumb: ...the things I do for you guys :lol:

Note stone wet pre test.

 

[evanvine]

the things I do for you guys

I suppose you need to fill the time somehow as you're not brewing. :whistle:
I'll just go and get my coat!

 

[dennisdk2000]

Apparently they need 15psi to drive them.
Is this true??

I have the 2 micron stones and they do take quite a wallop to get the air through, but I don't think it's anywhere near 15PSI. I think I used this pump originally and you had to be careful. Start the pump before the stone got wet...not probs, try and start it after...no way..or a great deal of difficulty.

I have my mini compressor handy so will give the airstone a go in a min and report back :thumb:

EDIT....no filter or non return valve (aquarium spring type) fitted and the air stone works at sub 2PSI, it actually reads less than half of 2! Will check with filter and nrv fitted next.

EDIT 2...same result with nrv and filter fitted :thumb: ...the things I do for you guys :lol:

Note stone wet pre test.

Thank you, Vossy, it's much appreciated! :thumb: :clap: :hat:

Suppose I feel a little better about this venture now... :| Really hopes it works and improves my beer!

Dennis

 

[Loetz]

ditto
:hat:

 

[grinling]

We have done a few kits into bottles and now kegs but read somewhere not to aerate the brew at any stage coz it promoted 'off' flavours. Were we completely misled? We should be aerating after adding the yeast, then? The beer seems to turn out perfectly OK. :hmm:

 

[MacKiwi]

I think the discussion is about aerating the wort before the pitching the yeast. The yeast utilize the oxygen to reproduce (I think, not 100% sure).

Aerating after fermentation is complete is considered a no-no, as it results in oxidisation and off-flavors. Oxygen added before pitching yeast doesn't stay in the wort long, as the yeast consume it...

 

[oz11]

MacKiwi is correct. Also kits tend to come with dry yeast which does not require aeration. If you start using liquid yeast or repitching from a previous brew then aeration at pitching time becomes beneficial/necessary*

*delete as per your own point of view :lol:

 

[wezil]

As a matter of interest, aeration does not in fact add oxygen at all, it merely aids the dispersal of CO2. Carbon dioxide is far more soluble in water than oxygen hence the use of aeration to drive it off

 

[oz11]

Sorry, but you are wrong, you can use oxygen through an airstone to add oxygen directly to the wort. Pre-fermentation there is no CO2 to drive off.

http://byo.com/stories/item/1894-aerati ... techniques

 

[wezil]

Hi, ALL water that we would use for brewing has carbon dioxide in it. And your link is just advertising not scientific fact, it's just a message to sell it's particular brand of air stone! Water will only hold so much oxygen, this is it's equilibrium point. If yeast or anything else use up this oxygen, it is replaced with oxygen from the air almost simultaneously. This is a scientific fact. Also to get oxygen enriched water or wort you would have to increase the atmospheric pressure or inject the oxygen as a fine mist. This will cause the liquid to become super saturated, which even yeast won't like. As pure oxygen is a strong oxidising agent it will burn our lungs and will do the same to yeast (medical oxygen has carbon dioxide added to make you exhale). Carbon dioxide is also many times more soluble in water than oxygen, hence aeration to drive it off!

 

[oz11]

:shock:

 

[Vossy1]

I think you've missed a crucial point Wezil
We are aerating wort which has been boiled for an hour and it's oxygen poor...not water!

Water will only hold so much oxygen, this is it's equilibrium point.

That is correct, but (in the case of water) you're assuming it comes with the equilibrium already reached which is not necessarily the case, in which case aeration can add O2.

And your link is just advertising not scientific fact, it's just a message to sell it's particular brand of air stone!

BYO is a magazine...do they sell or link air stones for purchase :hmm:
EDIT, I now see a linked shop on the BYO page.

 

[wezil]

Hi, the solubility of oxygen is dependent on temperature, the higher the less oxygen and vice versa. Boiling wort will have a bare minimum but as it cools it will return to 'normal' levels. However carbon dioxide is many times more soluble in 'water' than oxygen even at higher temps. It is this excess of carbon dioxide that is causing the oxygen to be less available to living organisms (in this case yeast) It is this CO2 that aeration drives off, it does not add oxygen (the meniscus round the bubble will prevent it from going into solution and thus making it available to living organisms). So aerating the wort is a good thing (just don't bother wasting money on oxygen) although not for the reasons usually given. And the more and smaller the bubbles (within reason) the better.

 

[Algernon]

MacKiwi is correct. Also kits tend to come with dry yeast which does not require aeration.

So does this mean as long as I am only using wilko's finest yeast then I need not worry about aeration before pitching? I made my first AG recently and I normally rely on the foamer attachment on my cold water tap to aerate water for kit beers. For AG all my water has been boiled and contains sod all oxygen. I gave it a sound beating with a slotted spoon but obviously I feel there is a balance to be struck between aerating one's wort and stirring in all manner of spores from the air and getting contamination.
If I can avoid doing this then until I up my game to using liquid yeast starters I would prefer to do so for peace of mind.

 

[unclepumble]

MacKiwi is correct. Also kits tend to come with dry yeast which does not require aeration.

So does this mean as long as I am only using wilko's finest yeast then I need not worry about aeration before pitching? I made my first AG recently and I normally rely on the foamer attachment on my cold water tap to aerate water for kit beers. For AG all my water has been boiled and contains sod all oxygen. I gave it a sound beating with a slotted spoon but obviously I feel there is a balance to be struck between aerating one's wort and stirring in all manner of spores from the air and getting contamination.
If I can avoid doing this then until I up my game to using liquid yeast starters I would prefer to do so for peace of mind.

If using Dried Yeast, DO NOT AERATE it is not required.
When aerating to aid yeast growth with liquid yeast, it depends on the yeast type and strain on how much you aerate, and the process you use to aerate, determines how much dissolved oxygen is left in the processed wort.

I would not bother using pure oxygen at home its a waste of money, simply spraying the wort into FV should surfice, and should give you around 8PPM dissolved oxygen, just about adequate for most yeasts ideal measurements are 8-12PPM (thats parts per million folks) for an ale yeast, Lager yeasts work better when you can get 12-16PPM dissolved oxygen.

YOU CAN ADD OXYGEN TO THE WORT BY USING THE CORRECT PROCESS IT WILL ENRICH, however why would you do it at home, how are you going to measure how much dissolved oxygen is in the wort, an oxygen analyzer costs thousands, & without one you risk adding too much, adding too much or not knowing how much you are adding each time can be worse than hand aerating or spraying in, as it can give very varied results, (yeast overgrowth, leading to high PG, stuck fermentations, etc). you can do more harm than good without being able to measure what you are doing to the wort, therefore don't waste your time and money when home brewing!

Better to follow a few simple steps and repeat them to the letter everytime you brew.

Dried Yeast
1/ always rehydrate before adding using warm water 30-35deg C at around 10-1 ratio therefore around 100-110ml otherwise you may not get the optimum amount of cells in your pitch (sprinkling will not give best results and is lazy)
2/ do not aerate, it is not required, and if you do its likely to cause yeast overgrowth, which in turn may affect your fermentation and finished beer, such as a high finishing gravity.
3/ do not use a yeast nutrient, it is not required

Liquid Yeast
1/ Always Aerate the wort, spraying into FV is the easiest and most repeatable method, & most likely to give you the best results and if done from start to finish of the transfer, likely to give to 8-10PPM of dissolved oxygen in the wort (adequate for an ale yeast), there are other methods like manifolds, adding pure oxygen etc, however how are you going to measure what you add or take away, & secondly & more importantly, the more complicated your method is for aerating, generally the more equipment you have to clean, and the greater the chance of adding unwanted micro-organisms, that could potentially infect your fermentation and yeast.

2/ Make sure you are pitching the correct amount of yeast for your fermentation, especially when repitching a slurry or skimming of liquid yeast, Mr Malty's yeast calculator is a handy tool (google it)

3/ Always use a good quality yeast nutrient, especially if your brew system has no copper in it, as the yeast need zinc, to reproduce effectivly, good quality yeast nutrients will have trace levels of zinc in them to overcome this.

Most of all Concentrate on keeping things simple, but ensure you stick to the same process each time, that way you will get the best and most repeatable results, & you will enjoy your hobby much better.

P.S. my grammar and punctuation is not so good in this post, but its late i'm tired and i cant be bothered to proof read it

Regards

Shane