Open fermentation experiment.

[BrewingTravisty]

I guess my question would be, if you are fermenting via open container, then follow up by taking all the conventional precautions found in a closed-container ferm (those that normally preclude oxidation, contamination, off-flavors, etc.), then why the open ferm to begin with?

IOW, all else being equal, what does an open container ferm to do benefit the beer?

All of the benefits of open fermentation happen during the main part of the fermentation (12-48 hours). Normally you would either rack to secondary before the krausen drops. What I've noticed from my small experiment is that the main thing that open fermentation has done has been to accentuate the flavors from the yeast. I'm getting breadier notes on the nose, a bit on the flavor and mostly fruitier esters in the flavor profile. Certain styles would definitely benefit promoting the yeast profiles, such as weizens and Belgians.

Now the reason you would follow conventional precautions is because you don't want to introduce too much in the way of oxidization, or contaminants. Once the krausen has fallen you no longer have any protection. Ideally you would rack before the krausen has fallen, because there may be contaminants floating on top of it.

I have also heard that the yeast are under less stress because of less pressure caused by c02 in a close space. Whether or not that is true I leave to your own research as my experiment wasn't in depth enough to figure that out. I can tell you that the fermentation finished out quicker than any other I have done, and it completely changed the taste of the beer I made. Where the original recipe was light and crisp, with a nice rye bite to it, the open ferment was very flavorful, with bready notes and a nice hint of apricot and slight tang to it, finishing with a more subdued rye bite. It also wasn't quite as crisp. So the benefits of it really depend on the style that you use it with.


All in all, this is just another tool that you can use to produce the beer that you imagine.

 

[passedpawn]

All of the benefits of open fermentation happen during the main part of the fermentation (12-48 hours). Normally you would either rack to secondary before the krausen drops. What I've noticed from my small experiment is that the main thing that open fermentation has done has been to accentuate the flavors from the yeast. I'm getting breadier notes on the nose, a bit on the flavor and mostly fruitier esters in the flavor profile. Certain styles would definitely benefit promoting the yeast profiles, such as weizens and Belgians.

Now the reason you would follow conventional precautions is because you don't want to introduce too much in the way of oxidization, or contaminants. Once the krausen has fallen you no longer have any protection. Ideally you would rack before the krausen has fallen, because there may be contaminants floating on top of it.

I have also heard that the yeast are under less stress because of less pressure caused by c02 in a close space. Whether or not that is true I leave to your own research as my experiment wasn't in depth enough to figure that out. I can tell you that the fermentation finished out quicker than any other I have done, and it completely changed the taste of the beer I made. Where the original recipe was light and crisp, with a nice rye bite to it, the open ferment was very flavorful, with bready notes and a nice hint of apricot and slight tang to it, finishing with a more subdued rye bite. It also wasn't quite as crisp. So the benefits of it really depend on the style that you use it with.


All in all, this is just another tool that you can use to produce the beer that you imagine.

Sorry, but the skeptic in me requires a control. If you're comparing open fermentation to closed, shouldn't you have the exact same beer in a closed fermentor to actually be able to make that comparison?

Further, aren't you a little premature here since the beer is far from finished? I'm not saying you introduced bacterial infection, in fact I really doubt it, but if you did that might not show up for a while. Wild yeast can also cause havoc in the flavor dept that you won't notice for a while.

I applaud your pioneering spirit, but I question the early conclusions.

 

[specharka]

Sorry, but the skeptic in me requires a control. If you're comparing open fermentation to closed, shouldn't you have the exact same beer in a closed fermentor to actually be able to make that comparison?

Further, aren't you a little premature here since the beer is far from finished? I'm not saying you introduced bacterial infection, in fact I really doubt it, but if you did that might not show up for a while. Wild yeast can also cause havoc in the flavor dept that you won't notice for a while.

I applaud your pioneering spirit, but I question the early conclusions.

+1

Brulosophy does a blind taste test with seasoned beer drinkers to determine the statistical significance of any purported outcome from their exbeeriments, IMO the only way it should be done. It's fun to experiment but if you don't have a control your results are just speculation.

I also think you might be experiencing confirmation bias -- the notion that you want to believe so strongly there is a difference in taste that your mind perceives it.

 

[BrewingTravisty]

Sorry, but the skeptic in me requires a control. If you're comparing open fermentation to closed, shouldn't you have the exact same beer in a closed fermentor to actually be able to make that comparison?

Further, aren't you a little premature here since the beer is far from finished? I'm not saying you introduced bacterial infection, in fact I really doubt it, but if you did that might not show up for a while. Wild yeast can also cause havoc in the flavor dept that you won't notice for a while.

I applaud your pioneering spirit, but I question the early conclusions.

The fermentation is complete, I'll be bottling it today. The control is a beer that I brewed a couple weeks ago, same recipe. I know that's probably not enough of a control for a skeptic, but I can tell you that the taste differences are major.



But, this wasn't meant to convince anyone of anything, just me documenting my experiences in a way that others can access and either take something from or not.

+1

Brulosophy does a blind taste test with seasoned beer drinkers to determine the statistical significance of any purported outcome from their exbeeriments, IMO the only way it should be done. It's fun to experiment but if you don't have a control your results are just speculation.

I also think you might be experiencing confirmation bias -- the notion that you want to believe so strongly there is a difference in taste that your mind perceives it.

My control is a beer already brewed and bottled, same exact recipe with the only difference being that one was open for the main fermentation and one was closed the entire time.

I can tell you, this is far from speculation and confirmation bias can only fool you so much. I might agree that that were a possibility if the flavors weren't completely different. I also never went in wanting to experience anything one way or another, besides my desire for it to not be a ruined batch lol.

The first batch I made with a closed bucket is dry and crisp, with a rye bite, slight bready/buscuitiness and no fruity esters to speak of. The open container version has a tang and a strong fruitiness, very much like apricots. The rye is very subdued by the fruit but still there enough to give a nice bite at the end and it's not quite as dry as the original.


Either way though, I wasn't expecting anyone to think this was some big and organized science experiment lol this all was mostly just to document my experiences and to share them with others.

 

[GHBWNY]

All of the benefits of open fermentation happen during the main part of the fermentation (12-48 hours). Normally you would either rack to secondary before the krausen drops. What I've noticed from my small experiment is that the main thing that open fermentation has done has been to accentuate the flavors from the yeast. I'm getting breadier notes on the nose, a bit on the flavor and mostly fruitier esters in the flavor profile. Certain styles would definitely benefit promoting the yeast profiles, such as weizens and Belgians.

Now the reason you would follow conventional precautions is because you don't want to introduce too much in the way of oxidization, or contaminants. Once the krausen has fallen you no longer have any protection. Ideally you would rack before the krausen has fallen, because there may be contaminants floating on top of it.

I have also heard that the yeast are under less stress because of less pressure caused by c02 in a close space. Whether or not that is true I leave to your own research as my experiment wasn't in depth enough to figure that out. I can tell you that the fermentation finished out quicker than any other I have done, and it completely changed the taste of the beer I made. Where the original recipe was light and crisp, with a nice rye bite to it, the open ferment was very flavorful, with bready notes and a nice hint of apricot and slight tang to it, finishing with a more subdued rye bite. It also wasn't quite as crisp. So the benefits of it really depend on the style that you use it with.


All in all, this is just another tool that you can use to produce the beer that you imagine.

I both agree with the above posters and I admire your adventuresome spirit. Above all else, HB'ing should be fun, and it sounds as if you're having fun with it. That said, I, too, would be cautious of drawing any premature conclusions re: the final outcome of the beer, esp. using only 2 batches by which to make firm conclusions about process effects. There are so many other variables in play with any given brew, that it would be difficult to assume that "this" step of the process definitely had "that" effect. Case in point, there are many homebrewers that have done the same brew/style hoping for the exact same results, and it sometimes doesn't come out exactly the same way due to some unknown variable.

The info I've seen for open-vat fermentation seems to imply the concept is best applied to very large-scale runs of beer. Where you have a long, flat, shallow vessels that may not be practical/possible to cover, I'm not sure that the same principles would necessarily apply to a many-times-scaled-down bucket version. Just sayin'. Nonetheless, I am interested in knowing the outcome of this beer 2 months from now. And thanks for being a 'guinea pig' at the possible expense of your beer while providing the info on this forum. Obviously, by the number of replies, the concept is of definite interest.

 

[BrewingTravisty]

I both agree with the above posters and I admire your adventuresome spirit. Above all else, HB'ing should be fun, and it sounds as if you're having fun with it. That said, I, too, would be cautious of drawing any premature conclusions re: the final outcome of the beer, esp. using only 2 batches by which to make firm conclusions about process effects. There are so many other variables in play with any given brew, that it would be difficult to assume that "this" step of the process definitely had "that" effect. Case in point, there are many homebrewers that have done the same brew/style hoping for the exact same results, and it sometimes doesn't come out exactly the same way due to some unknown variable.

The info I've seen for open-vat fermentation seems to imply the concept is best applied to very large-scale runs of beer. Where you have a long, flat, shallow vessels that may not be practical/possible to cover, I'm not sure that the same principles would necessarily apply to a many-times-scaled-down bucket version. Just sayin'. Nonetheless, I am interested in knowing the outcome of this beer 2 months from now. And thanks for being a 'guinea pig' at the possible expense of your beer while providing the info on this forum. Obviously, by the number of replies, the concept is of definite interest.

I completely agree with you, that I shouldn't take this one experiment to make a firm conclusion, and I can see from the claims I was making that I do seem to be making that mistake. All of my conclusions so far are mostly just citing information I've read, or just noting the differences that I see.

I do plan on doing a more extensive experiment of this when I am able to. I think I mentioned in a previous post that I would like to get some fermenters made for open fermentation, and do a 3 way split 10 gallon batch, with everything exactly the same except for the fermenters. At that point I'll go more scientific with the experiment and try to recruit a few judges and more experienced pallates to test it. At that point I might actually do a full article on it.

All in all, I am definitely having fun with this, and look forward to tasting the finished product. As well as doing more experiments in the future.

I appreciate your skepticism though! I don't want people reading too much into this thread, and thinking that my results are conclusive or even replicable.

 

[BrewingTravisty]

Just wanted to give some quick tasting notes on this beer, and how it's developed over the past couple weeks in the bottle.

Aroma: not a lot on the nose, faintly bready. I slight fruitiness. No hop aroma. Bread is the most prevalent aroma.

Appearance: slightly hazy. Could use some more time to clear. About 2.5-3 fingers of off white head on pour, dissipates fairly quickly but leaves a thin lacing on top, till beer is gone.

Mouthfeel: medium-light body, light carbonation bite.

Flavor: roastiness is upfront, fading into bready and fruity with just enough rye to know it's there. It has a more booziness than the 5.5%abv should have, but no hot or fusel alcohols. It probably needs a few more weeks to mellow out. The fruitiness has faded drastically since bottling but is still there with just enough of a hint of apricot to be pleasant.


All in all, definitely more fruity than my normal batches but I would have to do more in depth experiments to confirm anything. Next time I'll split the batch in 2, one open and one closed.

View attachment 1450401859614.jpg

 

[Gadjobrinus]

The reason I asked was a fellow brewing buddy tried open fermentations and used a sanitized spoon for the first day or two before transferring it to a closed fermenter. The Hefeweizen that he made using this method was amazing.

He had an open fermenter just like the one I have in the attached photos. Another brew club member made these for us. He was practicing his welding skills. I haven't gotten around to using it though. The lid overlaps the sides...

Sorry, I know, resurrecting. Had to shout it out: YIKES. Another part of the planning maelstrom.