Homebrewers Association | AHA Forum

General Category => Yeast and Fermentation => Topic started by: anotherdrummer on January 11, 2010, 09:29:09 PM

Title: Open Fermentation vs Closed Fermentation
Post by: anotherdrummer on January 11, 2010, 09:29:09 PM
I apologize in advance if this is a duplicate thread..

i've been doing some reading, and it looks like open vs closed fermentation is about as debated as free will vs predestiny. what are your thoughts on open vs. closed fermentation? what are the advantages of one over the other? i've always only done closed.

The reason I'm asking is I just finished a 14 gallon lager.  It's in my refrigerator at 55df.  My keggle-fermenter is a keggle with the lid of a plastic bucket sealing off the hole and an airlock in the middle.  The lid is surrounded with rubber and is then strapped down to the keggle to make it a really tight fit.  My issue is this...I pitched the starter for this beer Saturday night.  I see absolutely no movement in the airlock, but I can smell the fermentation.  My only concern is that there may be a leak somewhere in the seal, though not a very big one...at all.  I'm keeping the lager in this keggle for the duration of the entire fermentation, and not moving to secondary.  After d-rest, and temp drop...I'm thinking I should be fine...but I just kind of want a second (or third or fourth) opinion.

What do you think?
Title: Re: Open Fermentation vs Closed Fermentation
Post by: Kaiser on January 11, 2010, 09:37:20 PM
What you are doing is not necessarily considered open fermentation.

But I’d be worried that you pull air into the keggle when you lower the temperature to cold conditioning temps. We recently discussed this as the most likely case for the oxidation of a beer in this thread: http://www.homebrewersassociation.org/forum/index.php?topic=900.0

Kai
Title: Re: Open Fermentation vs Closed Fermentation
Post by: anotherdrummer on January 11, 2010, 09:51:56 PM
Hey Kaiser...yeah, it's not wide open, it's just not a "tight" seal.  I'm not even going to mess the lid until 8 weeks...then I'm going to remove the lid to transfer it into kegs and purge with CO2.

thanks for the link!
Title: Re: Open Fermentation vs Closed Fermentation
Post by: denny on January 11, 2010, 11:10:10 PM
It's my understanding that English style beers traditionally used and benefited from open fermentation.  It seems I even recall something about it affecting the ester profile.  Anybody know anything about that?
Title: Re: Open Fermentation vs Closed Fermentation
Post by: lonnie mac on January 11, 2010, 11:42:50 PM
I don't know if this is too hotly debated really... After all, beer is 10,000 years old and most of that is open fermentation! :)

For me, I have always fermented in a pot with a loose lid sitting on top. I lager this way too... Rarely if ever do I secondary unless it is a real big beer, or a lager... It works for me very well...

In your situation, I really wouldn't worry much... You have already gone to a much greater length that I ever have.

(http://www.alenuts.com/stuff/true.jpg)
Title: Re: Open Fermentation vs Closed Fermentation
Post by: Thirsty_Monk on January 12, 2010, 12:45:01 AM
It's my understanding that English style beers traditionally used and benefited from open fermentation.  It seems I even recall something about it affecting the ester profile.  Anybody know anything about that?
Czechs are still fermenting in open fermenters. I do not have proof but shalow fermenters create diferent ester profile.
Title: Re: Open Fermentation vs Closed Fermentation
Post by: Kaiser on January 12, 2010, 01:39:57 AM
I think it is more the depth of the fermenter that affects the ester profile. I started moving to a more open fermentation as well and eventually want to see how it compares to a carboy.

Kai
Title: Re: Open Fermentation vs Closed Fermentation
Post by: anotherdrummer on January 12, 2010, 02:58:31 AM
Thanks guys!  Denny, you're right..WAY better.  I'll post a pic of what it looks like.  It'll be blurry..  So basically a keggle with a bucket lid, with rubber around the lid.  The bungees are really tight and do a good job at holding the bucket lid down tight.  I've done one batch with this and it worked well...airlock was active.  This batch..not so much.


(http://i78.photobucket.com/albums/j83/AnotherDrummer_2006/Brewings/Ferm-Keg.jpg)
Title: Re: Open Fermentation vs Closed Fermentation
Post by: tom on January 12, 2010, 04:19:34 AM
Hey Kaiser...yeah, it's not wide open, it's just not a "tight" seal.  I'm not even going to mess the lid until 8 weeks...then I'm going to remove the lid to transfer it into kegs and purge with CO2.

thanks for the link!
8 weeks? That's a little longer than usual. Is that your usual method? Is the fridge at 55degF or the wort? The fermenting wort is usually hotter than the ambient temperature.
With lagers I usually primary for about 2 weeks at about 50 degF. With a big enough starter and adequate oxygen, you should be done primary within 2 weeks.
Title: Re: Open Fermentation vs Closed Fermentation
Post by: karlh on January 12, 2010, 12:38:15 PM
I have fermented with a similar set up many times and never had any issues.  I actually wish I had a fermenter set up like yours in addition to what I have.  My previous brewing partner manufactured his "keggle" fermenter lid with a larger cut lid from another keg (fermenter was cut to 11", another keg was cut to 12" and the 12" lid was used for the 11" hole).  On the stainless lid he used a bead of silicone which is safe at boiling temps, and wedges were used rather than rubber.  He could then boil water in the fermenter to sanitize.  With your bucket lid, you might be able to improve sealing/contact areas with a bead of silicone as well. 
Title: Re: Open Fermentation vs Closed Fermentation
Post by: babalu87 on January 12, 2010, 01:08:50 PM
FWIW I havent locked down the lid on a bucket OR put an airlock on a primary in over a year.

Quote
It's my understanding that English style beers traditionally used and benefited from open fermentation.  It seems I even recall something about it affecting the ester profile.  Anybody know anything about that?

Denny, I think there is something to the esters with the English yeasts.
1469 seems to throw more of the good stuff with tin foil "airlock" vs. a true airlock.
I havent done a side by side yet though, mostly because I am pragmatic  :P
Title: Re: Open Fermentation vs Closed Fermentation
Post by: bluesman on January 12, 2010, 02:46:49 PM
I'm no expert on open fermentation and frankly it kind of scares me, but apparently it is happening everyday in breweries around the world as this picture shows.

(http://blog.timesunion.com/beer/files/2009/10/ommegang-ferment.jpg)

A true top-cropping ale yeast in an open fermentor at Brewery Ommegang

I beleive the krausen layer on top somewhat protects the fermenting beer from the detrimental effects of oxidation during the process.
Title: Re: Open Fermentation vs Closed Fermentation
Post by: Thirsty_Monk on January 12, 2010, 04:05:31 PM
I beleive the krausen layer on top somewhat protects the fermenting beer from the detrimental effects of oxidation during the process.


To my understanding it is fermented in open fermenter till 75% of fermentation is done and CO2 is still been created.
Then it is transfered to close vessel and oxygen is purged out.
This way you do not get oxidation.
Title: Re: Open Fermentation vs Closed Fermentation
Post by: anotherdrummer on January 12, 2010, 04:16:43 PM
I say 8 weeks...but it will actually be more like 6.  I dont plan to transfer to a secondary.  I've done this recipe several times before and rushed it a few times before as well.  i'm just going to "set it and forget it".  well....of couse doing d-rest and such...but not lifting the lid for 6 weeks..
Title: Re: Open Fermentation vs Closed Fermentation
Post by: anotherdrummer on January 13, 2010, 01:59:09 AM
I'm no expert on open fermentation and frankly it kind of scares me, but apparently it is happening everyday in breweries around the world as this picture shows.

(http://blog.timesunion.com/beer/files/2009/10/ommegang-ferment.jpg)

A true top-cropping ale yeast in an open fermentor at Brewery Ommegang

I beleive the krausen layer on top somewhat protects the fermenting beer from the detrimental effects of oxidation during the process.


I had actually seen something about Sierra Nevada doing their Bigfoot Barleywine like that.
Title: Re: Open Fermentation vs Closed Fermentation
Post by: Kaiser on January 13, 2010, 05:37:35 AM
There is nothing scary about open fermentation as long as you can keep the fermentation room sanitary. This is much easier in a brewery than a basement. It also helps having means of monitoring contamination levels in yeast and beer.

Kai
Title: Re: Open Fermentation vs Closed Fermentation
Post by: ndcube on January 13, 2010, 01:31:35 PM
There is nothing scary about open fermentation as long as you can keep the fermentation room sanitary. This is much easier in a brewery than a basement. It also helps having means of monitoring contamination levels in yeast and beer.

Kai

You mean like a microscope...
Title: Re: Open Fermentation vs Closed Fermentation
Post by: bluesman on January 13, 2010, 02:42:46 PM
I think he's on the lookout for "things" and "stuff".  ;D
Title: Re: Open Fermentation vs Closed Fermentation
Post by: hankus on January 13, 2010, 03:55:09 PM
Mom and Pop german brewries as well as Sam Smith's use open technique but only 'til 3/4 fermented and co2 pressure and krausen begin to fall and then they go closed
Title: Re: Open Fermentation vs Closed Fermentation
Post by: Kaiser on January 13, 2010, 04:03:48 PM
You mean like a microscope...

Not just a microscope but also selective growth media that can be used to grow contaminations while suppressing the yeast. While that cannot be used to make a real time assessment of the contamination levels it can be used to detect trends. Once you have enough contamination that you can see it with a microscope it might be too late.

My general advice is to start out with closed fermentation and get comfortable with the process and make some good beers. Once you feel confident and want to give a more open fermentation a try, go for it. Just keep in mind that you may be playing much closer to the edge of getting an infection in your beer. But maybe there is something about open fermentation that works well for some beers and the added effort and risk may be worth it. Unless we don’t shy away from it and give try we won’t find out. You don’t need a microscope or micro biology lab to handle open fermentation as a home brewer. Your palate should be sufficient.  The stakes for commercial brewers are much higher but many believe that it makes their beer better even though it increases the risk of contamination and requires them to create sanitary rooms.

Kai


Title: Re: Open Fermentation vs Closed Fermentation
Post by: bluesman on January 13, 2010, 05:14:25 PM
You mean like a microscope...

My general advice is to start out with closed fermentation and get comfortable with the process and make some good beers. Once you feel confident and want to give a more open fermentation a try, go for it. Just keep in mind that you may be playing much closer to the edge of getting an infection in your beer.
Kai


I guess I should rephrase what I said "kind of scares me". What I should have said is that open fermentation has some potential to develop an infection, therefore I am not willing to take that risk. I am more interested in developing new recipes and brewing processes that involve automation. I'm a gadget guy...I like experimenting with process controls.

There's nothing wrong per say with experimenting in open fermentation, it's just not where my interests lie. I would suggest researching The Brewery Ommegang's process. Maybe they will let you in on their techniques.  :-\
Title: Re: Open Fermentation vs Closed Fermentation
Post by: anotherdrummer on January 13, 2010, 05:35:41 PM
all i usually so is closed.  this was an accident or just plain screw up.  either way, i have it in my lager refrigerator at 55..i just don't know where the seal compromise is.  i'm not going to try and find out right now!!  :)