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Date: 11 Dec 2006 07:36:20
From: Sportinus
Subject: Wort Aeration
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In looking thru the group about wort aeration, I'm a little confused on
the best way to aerate the wort. It seems to me that there are 2
preferred methods of aerating, aquarium pump and canned oxygen (do you
still need a filter with canned oxygen?). The consensus seems to be
aquarium pump foe at least 6 hours or canned oxygen for up to 2
minutes. Do you pitch the yeast prior to oxygeniation? Is one way
better than the other? What are the plus and minus of each way?
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Date: 11 Dec 2006 16:42:20
From: John 'Shaggy' Kolesar
Subject: Re: Wort Aeration
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On 11 Dec 2006 07:36:20 -0800, <sportinus@yahoo.com > wrote:
> In looking thru the group about wort aeration, I'm a little confused on
> the best way to aerate the wort. It seems to me that there are 2
> preferred methods of aerating, aquarium pump and canned oxygen (do you
> still need a filter with canned oxygen?). The consensus seems to be
> aquarium pump foe at least 6 hours or canned oxygen for up to 2
> minutes. Do you pitch the yeast prior to oxygeniation? Is one way
> better than the other? What are the plus and minus of each way?
I use a Mix-stir aerator (basically a fancy paint stirrer that mounts
on a drill). Cheap and effective.
I usually pitch after aeration, but it probably doesn't make a real
significant difference.
John.
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Date: 11 Dec 2006 08:41:03
From:
Subject: Re: Wort Aeration
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Yeast need oxygen to build up their store of various materials
(sterols, fatty acids, etc) before the ferment. But there are a lot of
ways to build up this store, and not all of them involve putting oxygen
in your wort.
One is to use dry yeast. The dry yeast manufacturers build up the
yeasts' store of these materials at the factory--therefore additional
oxygen is not necessary. This is their claim, and also what I (and
many others) have experienced. Obviously you still need to pitch a
sufficient quantity of yeast, which is another side of the same coin.
Another method, using liquid yeast, is to charge up the yeast by
providing them with lots of oxygen while they are still in the starter,
before they are pitched into the wort. If this is properly done then
the wort really and truly does not need to be aerated. I think Bass
uses this process on commercial scale. One way to do it: build up a
truly sufficient quantity of yeast in a large starter, and then
"recharge" that batch of yeast by giving it another cup of wort and
repeatedly aerating it with violent shaking over the course of a few
hours. Another way: repeately (several times per day) aerate the
starter while it grows.
For me (but not everyone), these methods are preferable to directly
aerating the wort. But I have found that if you only pretend to give
the yeast lots of oxygen in the starter, it doesn't work. If you make
a big starter and just aerate it once, at the beginning, you will grow
a lot of cells but they will be depleted may perform poorly in the
beer. To be reliable, they need to be recharged to full strength.
This can be done either at the dry yeast factory, in the starter, or in
the beer itself, depending on how you want to do it.
Baums
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Date: 11 Dec 2006 10:13:23
From: The Artist Formerly Known as Kap'n Salty
Subject: Re: Wort Aeration
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Sportinus wrote:
> In looking thru the group about wort aeration, I'm a little confused on
> the best way to aerate the wort. It seems to me that there are 2
> preferred methods of aerating, aquarium pump and canned oxygen (do you
> still need a filter with canned oxygen?). The consensus seems to be
> aquarium pump foe at least 6 hours or canned oxygen for up to 2
> minutes. Do you pitch the yeast prior to oxygeniation? Is one way
> better than the other? What are the plus and minus of each way?
>
I use O2 -- the main advantage is that you get full saturation in a
minute or so, so it's fast and sanitary. The disadvantage is that you
need extra stuff, like a stone regulator and then an O2 bottle (easy to
find, though).
Other possibilities include aquarium pumps, venturi arrangements, etc.
--
(Replies: cleanse my address of the Mark of the Beast!)
Teleoperate a roving mobile robot from the web:
http://www.swampgas.com/robotics/rover.html
Coauthor with Dennis Clark of "Building Robot Drive Trains".
Buy several copies today!
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Date: 11 Dec 2006 08:00:28
From:
Subject: Re: Wort Aeration
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Sportinus wrote:
> In looking thru the group about wort aeration, I'm a little confused on
> the best way to aerate the wort. It seems to me that there are 2
> preferred methods of aerating, aquarium pump and canned oxygen (do you
> still need a filter with canned oxygen?). The consensus seems to be
> aquarium pump foe at least 6 hours or canned oxygen for up to 2
> minutes. Do you pitch the yeast prior to oxygeniation? Is one way
> better than the other? What are the plus and minus of each way?
A mix-stir aerator (think paint stirrer) works great and takes maybe
2-3 minutes to do the job. I even have aquarium stuff lying around and
I haven't used it for aerating wort - the stirrer works fine and is
trivially easy to clean and sanitize.
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Date: 11 Dec 2006 09:52:20
From: hankus
Subject: Re: Wort Aeration
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Why not put a plastic Tee on the end of the wort to fermenter delivery
tube?- making sure that the venturi ID is < the in/out ID.The venturi effect
sucks in lotsa air (20% O2) and you will have ALL the aeration you
need.Aerating the yeast before pitching is wise,best done cold (better O2
absorption).A chef's whip works great-on a hand held mixer even better
--
Thanks
Hank
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Date: 11 Dec 2006 16:45:51
From: Ryan Case
Subject: Re: Wort Aeration
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Sportinus wrote:
> In looking thru the group about wort aeration, I'm a little confused on
> the best way to aerate the wort. It seems to me that there are 2
> preferred methods of aerating, aquarium pump and canned oxygen (do you
> still need a filter with canned oxygen?). The consensus seems to be
> aquarium pump foe at least 6 hours or canned oxygen for up to 2
> minutes. Do you pitch the yeast prior to oxygeniation? Is one way
> better than the other? What are the plus and minus of each way?
>
I pump into my bottling bucket and then put it on a shelf about 4' off
the ground and open the spigot to let it drain into my fermenter with
the starter slurry already in it. In a 12 gallon plastic fermenter I can
get a 6" head of foam on the top of 10 gallons of beer this way. My lag
times are low and it is free.
Ryan
--
Uuuurrrrp!
-Homer Simpson
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Date: 11 Dec 2006 12:50:09
From: Sportinus
Subject: Re: Wort Aeration
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John 'Shaggy' Kolesar wrote:
> On 11 Dec 2006 11:31:00 -0800, <sportinus@yahoo.com> wrote:
> >
> > Has anyone done a comparison to see if the aeration ways are equal?
>
> Define "equal". If you get the worts saturated to the same level, then
> the actual method doesn't make any difference. Studies have been done in the
> past that say if you use an oxygen tank for X minutes, you'll achieve Y%
> saturation, if you use an aquarium pump you'll achieve Z%... etc. I
> don't think any of them included the Mix-Stir though, the studies I know
> of were all done a long time ago.
>
> My feeling is that with either an oxygen tank or the mix stir, you only
> need to go for a couple minutes. The aquarium pump takes longer, but I
> don't know how much longer off the top of my head.
>
> > You could make 15 gal and split into 5 gallon batches and aerate the 3
> > different ways (Mix-stir, aquarium pump, canned oxygen) then see if
> > they attenuate (is that the right word?) differently.
>
> As long as you hit the same level of saturation, then there shouldn't be
> any other variables dependent on the aeration method. In that sense,
> they're all "equal".
>
>
> John.\
I think the interesting part would be to see if they really hit the
same level. It would also be interesting to see what it would take to
get it all at the same level.
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Date: 11 Dec 2006 21:49:47
From: John 'Shaggy' Kolesar
Subject: Re: Wort Aeration
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On 11 Dec 2006 12:50:09 -0800, <sportinus@yahoo.com > wrote:
> I think the interesting part would be to see if they really hit the
> same level. It would also be interesting to see what it would take to
> get it all at the same level.
I think they will hit an effective level, the only difference is going to
be how long it will take.
The one reference I've seen mentioned lately was from Al Korzonas's
Homebrewing Vol.1 pp. 115-117, quoting some tests done by A. J. deLange and
posted to the HBD. Three experiments mentioned. The third was a comparison of
"... bubbling compressed air through an airstone [aka an aquarium pump] with
gentle swirling and bubbling oxygen through an airstone [aka an oxygen tank]
with gentle swirling"
Using oxygen hit a value of 145% saturation in 2 min. Compressed air 90% in
5 min and 98% in 8 min.
John.
Note: Thanks to Don for posting this recently in the "Get it Right AG - misc
details" thread.
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Date: 11 Dec 2006 12:00:31
From: Vladimir
Subject: Re: Wort Aeration
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Sportinus wrote:
> In looking thru the group about wort aeration, I'm a little confused on
> the best way to aerate the wort. It seems to me that there are 2
> preferred methods of aerating, aquarium pump and canned oxygen (do you
> still need a filter with canned oxygen?). The consensus seems to be
> aquarium pump foe at least 6 hours or canned oxygen for up to 2
> minutes. Do you pitch the yeast prior to oxygeniation? Is one way
> better than the other? What are the plus and minus of each way?
I use an aquarium pump with an in-line filter and a diffusion stone,
usually for 20 minutes. Besides the initial expense of $35 and the 20
minute wait, I don't know of any other down side.
-Vladimir
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Date: 11 Dec 2006 11:31:00
From: Sportinus
Subject: Re: Wort Aeration
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Has anyone done a comparison to see if the aeration ways are equal?
You could make 15 gal and split into 5 gallon batches and aerate the 3
different ways (Mix-stir, aquarium pump, canned oxygen) then see if
they attenuate (is that the right word?) differently.
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Date: 11 Dec 2006 20:16:12
From: John 'Shaggy' Kolesar
Subject: Re: Wort Aeration
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On 11 Dec 2006 11:31:00 -0800, <sportinus@yahoo.com > wrote:
>
> Has anyone done a comparison to see if the aeration ways are equal?
Define "equal". If you get the worts saturated to the same level, then
the actual method doesn't make any difference. Studies have been done in the
past that say if you use an oxygen tank for X minutes, you'll achieve Y%
saturation, if you use an aquarium pump you'll achieve Z%... etc. I
don't think any of them included the Mix-Stir though, the studies I know
of were all done a long time ago.
My feeling is that with either an oxygen tank or the mix stir, you only
need to go for a couple minutes. The aquarium pump takes longer, but I
don't know how much longer off the top of my head.
> You could make 15 gal and split into 5 gallon batches and aerate the 3
> different ways (Mix-stir, aquarium pump, canned oxygen) then see if
> they attenuate (is that the right word?) differently.
As long as you hit the same level of saturation, then there shouldn't be
any other variables dependent on the aeration method. In that sense,
they're all "equal".
John.
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Date: 12 Dec 2006 11:23:31
From:
Subject: Re: Wort Aeration
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>
> I pump into my bottling bucket and then put it on a shelf about 4' off
> the ground and open the spigot to let it drain into my fermenter with
> the starter slurry already in it. In a 12 gallon plastic fermenter I can
> get a 6" head of foam on the top of 10 gallons of beer this way. My lag
> times are low and it is free.
Not to single out any of these techniques but is there
no issue with infection and the ones where alot of
additional air would be passed through the wort.
The mixing sticks or carboy shaking pass no large
amounts of air through but aeration stones especially
and pouring the wort from high distances seem
inherently infectious.
Although one could argue that any air could contain
the actual infectionous agent it would seem more
is worse.
Don
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Date: 13 Dec 2006 21:09:18
From: John 'Shaggy' Kolesar
Subject: Re: Wort Aeration
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On 12 Dec 2006 11:23:31 -0800, <dshesnicky@yahoo.com > wrote:
> Not to single out any of these techniques but is there
> no issue with infection and the ones where alot of
> additional air would be passed through the wort.
> The mixing sticks or carboy shaking pass no large
> amounts of air through but aeration stones especially
> and pouring the wort from high distances seem
> inherently infectious.
I think you would usually put a filter on the aquarium air pump so
that you didn't need to worry about it. I doubt pouring it from
a height would really introduce any ignificant risk. IMO, you're
probably getting a little too worried about it.
John.
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