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Author Topic: pure O2 tank accessories?  (Read 4123 times)

Offline fredthecat

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Re: pure O2 tank accessories?
« Reply #45 on: June 20, 2021, 02:36:13 pm »
this is one of a few reasons im purposely lowering my OGs slightly and greatly reducing the number of high gravity brews im making this coming year. at an OG of 1.045 or less i think the O2 is not really an issue at a level i would care about. but where i struggled a lot was higher OG attempts.

It is not that O2 is less of an issue with lower gravity wort.  It is that the O2 saturation level is higher in lower gravity wort.  This phenomenon can be seen on table 1 of the Kirsop publication that I linked in a previous post.  The reason why we pitch more yeast into high gravity wort is because it is more difficult to dissolve O2 in high gravity wort coupled with the high osmotic pressure that wants to draw the water out from inside of the yeast cells, resulting in a loss of turgor pressure, which can cause premature cell death.  In effect, we need more yeast cells because it is more difficult to grow the yeast biomass coupled with the threat of early cell death.


Quote
i also did take some advice from this forum on the idea of starters and will be improving that.

im aiming to just use the venturi effect spray. but i am trying saccharomyces' concept of -healthy, vitalized yeast but not a massive starter and ideal growing conditions. not simply a massive starter. i want to increase the yeast character in the beer

A venturi is not a spraying device.  A venturi is a device that causes a rapid drop in pressure resulting the creation of vacuum that sucks in air and mixes it with the liquid.

The venturi shown below is made from piece of 1/4" ID, 3/8" OD racking cane.  While it appears to do so at first glance, wort does not spray out of the holes due to Bernoulli's principle.  The ID is the typical racking plastic hose is 5/16" or 3/8".   The ID of the venturi is 1/4".  This reduction in diameter causes an increase in fluid flow while simultaneously causing a reduction in pressure.  The result is that air is sucked in through the holes and mixed with the wort while passing through the acrylic tubing when it is held vertical.  We are taking advantage of physics to aerate our wort.  One needs to be careful with the fluid flow rate because the foam head on the wort can grow to five or more inches. 



ok, but it will increase the beers drinkability and hoppy smoothness, right?

Offline denny

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Re: pure O2 tank accessories?
« Reply #46 on: June 20, 2021, 03:06:05 pm »
this is one of a few reasons im purposely lowering my OGs slightly and greatly reducing the number of high gravity brews im making this coming year. at an OG of 1.045 or less i think the O2 is not really an issue at a level i would care about. but where i struggled a lot was higher OG attempts.

It is not that O2 is less of an issue with lower gravity wort.  It is that the O2 saturation level is higher in lower gravity wort.  This phenomenon can be seen on table 1 of the Kirsop publication that I linked in a previous post.  The reason why we pitch more yeast into high gravity wort is because it is more difficult to dissolve O2 in high gravity wort coupled with the high osmotic pressure that wants to draw the water out from inside of the yeast cells, resulting in a loss of turgor pressure, which can cause premature cell death.  In effect, we need more yeast cells because it is more difficult to grow the yeast biomass coupled with the threat of early cell death.


Quote
i also did take some advice from this forum on the idea of starters and will be improving that.

im aiming to just use the venturi effect spray. but i am trying saccharomyces' concept of -healthy, vitalized yeast but not a massive starter and ideal growing conditions. not simply a massive starter. i want to increase the yeast character in the beer

A venturi is not a spraying device.  A venturi is a device that causes a rapid drop in pressure resulting the creation of vacuum that sucks in air and mixes it with the liquid.

The venturi shown below is made from piece of 1/4" ID, 3/8" OD racking cane.  While it appears to do so at first glance, wort does not spray out of the holes due to Bernoulli's principle.  The ID is the typical racking plastic hose is 5/16" or 3/8".   The ID of the venturi is 1/4".  This reduction in diameter causes an increase in fluid flow while simultaneously causing a reduction in pressure.  The result is that air is sucked in through the holes and mixed with the wort while passing through the acrylic tubing when it is held vertical.  We are taking advantage of physics to aerate our wort.  One needs to be careful with the fluid flow rate because the foam head on the wort can grow to five or more inches. 



ok, but it will increase the beers drinkability and hoppy smoothness, right?

I can't tell if this is supposed to be a joke or not...
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Offline jjflash

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Re: pure O2 tank accessories?
« Reply #47 on: June 21, 2021, 09:19:16 pm »
Low OG wort < 1.060 is very forgiving of technique.
Minimal aeration is all that is needed.
Higher OG wort > 1.060 is less forgiving of technique.
Then factor in the yeast type.
1056 is very forgiving of technique.
Belgian yeasts in high gravity wort are less forgiving.
The answer relates to OG and yeast type.
I follow the advice from the big book - Handbook of Brewing, Priest & Stewart.
They recommend O2 1ppm per degree Plato.
I use in-line O2 into the conical fermentor.
Easy technique with big beers and large volumes.
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Offline goose

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Re: pure O2 tank accessories?
« Reply #48 on: June 22, 2021, 07:59:40 am »
You can also make an effective aerator out of a piece of racking cane and allow physics to do the work for you (my current version is made from 1/2" OD 1/4" ID acrylic tubing, so that it fits 3/8" ID silicone tubing tightly). This aerator design is a based on the Bernoulli principle. The reduction in diameter causes an increase in fluid speed while causing a corresponding drop in fluid pressure through the aerator.  The combination increased fluid speed and decreases fluid pressure creates a vacuum that sucks air in through the holes and mixes it with the wort.  It is a very effective aerator design.



Sorry I am bit late to the party on this.

I do exactly the same thing Mark, although mine is made out of a piece of copper tubing with a bunch of holes drilled in it at an angle.  It works great.
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