Author Topic: Open fermenting a Saison  (Read 2000 times)

Offline gordonstrong

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Re: Open fermenting a Saison
« Reply #15 on: April 05, 2011, 02:18:16 PM »
I've been trying for at least the last 10 years to get data on that.  It was one of the things I asked Stan to ask brewers about while he was researching BLAM.  I remember asking about it at a Spirit of Belgium in DC a long time ago.  I've brought it up with several professional brewers.  I don't think there is much research on it, so all I have is experimental results.  I'm guessing it's something akin to the open fermenter concept, in that there is less pressure on the yeast.  That doesn't explain what's happening on a biological level, obviously.  I should check and see if there's anything on it in the new yeast book.
Gordon Strong • Beavercreek, Ohio • AHA Member since 1997 • Twitter: GordonStrong

Offline denny

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Re: Open fermenting a Saison
« Reply #16 on: April 05, 2011, 02:24:18 PM »
But it's something that you've personally experimented with and confirmed the results?
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Offline gordonstrong

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Re: Open fermenting a Saison
« Reply #17 on: April 05, 2011, 02:31:48 PM »
Personally run the experiments?  No.  Personally tasted the results of someone else's experiments?  Yes.
Gordon Strong • Beavercreek, Ohio • AHA Member since 1997 • Twitter: GordonStrong

Offline denny

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Re: Open fermenting a Saison
« Reply #18 on: April 05, 2011, 02:33:55 PM »
Good enough.  Thanks.  If I had an easy way to test the theory, I would.  Guess it's time to put my thinking cap on.
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Offline gordonstrong

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Re: Open fermenting a Saison
« Reply #19 on: April 05, 2011, 02:41:16 PM »
The person running the experiments worked in the food industry, so he had access to some large shallow food-grade bins.  If you don't want to use those as open fermenters, put some saran wrap over them.
Gordon Strong • Beavercreek, Ohio • AHA Member since 1997 • Twitter: GordonStrong

Online morticaixavier

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Re: Open fermenting a Saison
« Reply #20 on: April 05, 2011, 03:46:52 PM »
one of those large plastic tupperware type food service bins might work. the ones that are 24" by 18" by 5" or 6" deep. they usually have a snap on lid that could be drilled for a airlock even.
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Offline Mark G

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Re: Open fermenting a Saison
« Reply #21 on: April 05, 2011, 04:04:35 PM »
I've done some experimentation with open fermenting hefe's, and really didn't notice much of a difference in esters or phenols. I think that on a homebrew scale, the difference in head pressure has minimal impact. With a saison, you should get plenty of yeast character regardless. Let us know your results though. The only way to find out is to try.
Mark Gres

Offline Will's Swill

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Re: Open fermenting a Saison
« Reply #22 on: April 05, 2011, 05:44:24 PM »

It could because of the reduced pressure and the extra O2 would allow more yeast growth, giving more byproducts.  It seems unlikely to be a noticeable effect though.

What extra O2?  I thought a CO2 blanket protected the beer form O2?  ???  ;D
Is that a counter-pressure bottle filler in your pocket, or are you just happy to see me?

Offline denny

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Re: Open fermenting a Saison
« Reply #23 on: April 06, 2011, 08:59:11 AM »
I've done some experimentation with open fermenting hefe's, and really didn't notice much of a difference in esters or phenols. I think that on a homebrew scale, the difference in head pressure has minimal impact.

That was also my experience the couple times I tried it.
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Offline chumley

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Re: Open fermenting a Saison
« Reply #24 on: April 06, 2011, 09:48:09 AM »
I have open fermented bitters with WLP023 Burton and WY1968 Fullers yeast, and I do believe you get more fruity esters compared to fermenting closed (glass carboy for me) primaries.  The WLP023 yeast in particular gives nice apple/pear esters that is pretty much absent in the closed version.

I think that Tom is right....the increased yeast growth resulting from more oxygen available is the reason.

Our club is currently having a SMA2H brew going....10 of us are brewing the same ESB recipe with WY1968, with the only variable is that we are using different base malt.  But I maybe the only one doing an open ferment (I always do with WY1968)....it will be interesting to see if that makes a taste difference when we compare the ESBs at our May meeting.

I haven't tried open fermenting in a weizen, though...I am intrigued.

Offline tschmidlin

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Re: Open fermenting a Saison
« Reply #25 on: April 06, 2011, 10:18:14 AM »
I think that Tom is right....the increased yeast growth resulting from more oxygen available is the reason.
I just want to point out that I was speaking hypothetically, and that I said:

It seems unlikely to be a noticeable effect though.

Another possible explanation is the oxidation of various compounds can lead to flavor complexity.  I'm just throwing stuff out, not saying any of these are certainly the cause.
Tom Schmidlin

Offline samgamgee

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Re: Open fermenting a Saison
« Reply #26 on: April 13, 2011, 05:20:23 PM »
I think the oxygen added is negligible because the krausen and CO2 are going to blanket the fermenting beer and protect it. It's all about fermentor geometry and hydrostatic pressure. Increased CO2 concentrations inhibit ester production, and the deeper the fermentor is, the more CO2 stays in solution because of the hydrostatic pressure. This has been well documented in commercial trials and is published in Brewing With Wheat if I remember correctly, though I've heard it taught in Germany as well when I was over there. You can get a similar ester profile in a CCV with a low enough height-to-width ratio, but most CCVs are just a lot taller than open fermentors. Then the geometry affects convection currents, which also affect CO2 in solution. On a homebrew scale, I see no reason why not covering a carboy or bucket would do anything. The pressure under the airlock is probably negligible to the CO2 levels in solution. A super-shallow pan for a fermentor? I could see that maybe having an affect, but can't say for myself.