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Old 03-25-2013, 03:28 PM   #31
MagicSmoker
 
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Quote:
Originally Posted by freisste View Post
Right. I know there are ways to pressurize beer. I was trying to figure out a way to pressurize without allowing extra gas to be absorbed into the liquid (like the conditions at the bottom of a very large fermenter where the pressure comes from the depth of the liquid, not the pressurized headspace).

But that is interesting information.
The pressure at the bottom of a cylindrical tank will be the same regardless of diameter, so...
If you want to simulate a tall fermenter without requiring a huge volume of liquid for your test, then make it out of 3/4" SCH 40 PVC pipe.

Reason: clarification

 
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Old 03-26-2013, 12:38 AM   #32
Dynachrome
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I like that I have an envelope house.

I could do one about twenty feet tall in the sunroom.
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Old 03-26-2013, 02:38 PM   #33
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Quote:
Originally Posted by MagicSmoker

The pressure at the bottom of a cylindrical tank will be the same regardless of diameter, so...
If you want to simulate a tall fermenter without requiring a huge volume of liquid for your test, then make it out of 3/4" SCH 40 PVC pipe.
I actually imagined that, but assumed it was impractical. If it is practical, I think it is a good way to simulate the big boys. As you say, diameter is irrelevant to pressure.

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Old 03-28-2013, 07:03 AM   #34
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Hmm. The long tube is a good idea.

I hate to bring this up, but yeast cannibalization is a different process then autolysis. Inducing it through denial of nutrients, or excessive yeast stress, isn't going to produce any useful data. Autolysis occurs as a result of the enzymes present in the yeast cell after death. I rather doubt the chemicals, and therefore flavors, are the same.
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Old 04-06-2013, 05:54 PM   #35
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Quote:
Originally Posted by Leadgolem View Post
Hmm. The long tube is a good idea.

I hate to bring this up, buy yeast cannibalization is a different process then autolysis. Inducing it through denial of nutrients, or excessive yeast stress, isn't going to produce any useful data. Autolysis occurs as a result of the enzymes present in the yeast cell after death. I rather doubt the chemicals, and therefore flavors, are the same.
I read this earlier, it didn't filter through though.

Are you saying that my growler experiment is too small?
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Old 04-06-2013, 06:07 PM   #36
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My thought was the following:

People always say autolysis is a homebrew myth that the big boys deal with because their fermenters are so large. The size leads to higher pressure. This is a simple way to simulate the pressure the big boys get.

If you don't use a long tube (or similar) you can likely still achieve a condition which causes autolysis. Similarly, if you DO use it, you may NOT achieve the situation. It was just a thought that I thought might help.

 
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Old 04-06-2013, 07:24 PM   #37
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Ha, This reminds me of an older discussion:

marcelo's build idea

....Now, what 'bout "food safe PVC"?

If I'm going to do it, I might as well be able to use it for regular fermenting.
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Old 04-07-2013, 06:18 AM   #38
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Quote:
Originally Posted by Dynachrome View Post
I read this earlier, it didn't filter through though.

Are you saying that my growler experiment is too small?
Not exactly. Your growler experiment is a reasonable first experiment. I just don't think it will be definitive by it's self. There are still a fair number of factors that haven't been accounted for with that experiment.

Mostly, I was trying to point out that beating up on live yeast wasn't a useful thing to do when you are trying to study autolysis. It isn't any trick at all to induce yeast cannibalization, which we already know produces off aromas and negatively effects flavor.

Quote:
Originally Posted by freisste View Post
My thought was the following:

People always say autolysis is a homebrew myth that the big boys deal with because their fermenters are so large. The size leads to higher pressure. This is a simple way to simulate the pressure the big boys get.

If you don't use a long tube (or similar) you can likely still achieve a condition which causes autolysis. Similarly, if you DO use it, you may NOT achieve the situation. It was just a thought that I thought might help.
Pressure is one of the factors that the growler experiment does not account for. However, I'm not sure it's necessary to account for it. If you are running the experiment for primary scientific reasons, then yes. A long tube or some other method to simulate the pressure of a larger fermentor would be useful. If you are only interested in autolysis as it effects, or doesn't, homebrew then it isn't necessary. Homebrewers don't typically have fermentors that are deep enough to produce the pressure you are talking about.

Another factor that had occured to me is the chemical composition of the brew it's self. PH, mineral and/or salt content. I seem to remember salt being used to encourage autolysis in soy sauce production. I'll see if I can dig up the reference. Temperature also springs to mind. After all, why is it that so many sources recommend aging at cellar temps?

EDIT: This wasn't the original reference, but it works I think.
http://en.wikipedia.org/wiki/Yeast_extract
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Old 04-08-2013, 12:07 AM   #39
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Yeah, I'm trying to roughly duplicate regular home brew conditions.

The tall tube fermentor is probably fairly well off track.

No basement heaters.
No sunlight warming it up.
Small, but not un-imaginal size fermentor.

My thesis: What happens when you let your beer sit on a yeast cake for "an extended" period of time.
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Old 04-09-2013, 01:02 AM   #40
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