Open Fermentation

[Effect]

So after hearing about Yorkshire squares, seeing the Sierra Nevada Bigfoot fermentation video and reading up about this older style of fermentation I thought I would bring this one up for a bit of discussion.

If you are wanting to know a bit more about open fermentation, have a look here:

Open vs Closed Fermenters (homebrew scale)

BYO article on open fermentation

Sierra Nevada Bigfoot

White Rabbit open fermentation pics

There are many brewers who will praise and criticise open fermentation, but you will have to admit, if it is talked about by the pros there must be something about it. Belgian abbey and trappist brewers were quite hesitant to change the fermentation vessels as they believed that the quality of the beer will change by the type of fermenters. So if you have ever used open fermentation, please let us know your experiences with it.

I have never done any open fermentation. To me it seems that one would be having a very lax view on cleanliness. But is there any difference in the quality and complexity of the beer? Is it really just the difference in the size and dimensions of fermenter and not that the lid is open? Quite interesting none the less...I have two 50litre kegs sitting out the back of my house, that I maybe could manipulate one into being an open fermenter. But I am just still worried about sanitation.

Cheers
Phil

 

[manticle]

My guess is that most commercial breweries would be far more capable of controlling microbes in their open fermentation areas than we would.

Anything and everything that's been tried is probably worth trying once- this is just what would make me pause for thought.

 

[Nick JD]

I did it for about 3 years, about 20 years ago. Never had an infected brew - although my flatmate at the time did. We used to do double brews in a big drum that had no lid - a clean teatowel over the top.

You really needed to bottle at FG though, that's how my flattie's brew vinegared IIRC; and a good, healthy rearing to go yeast is essential.

Yeast doesn't like to share the sugaz if it can help it.

EDIT: I'm not sure if you'd notice any difference in taste, but would be interested to hear if anyone does. I was doing K&K back then so it all tasted like 6% "homebrew". Ahhh, to be a student again...

 

[kelbygreen]

i watched a video on it last night its on brewingtv and he said that you need to rouse the yeast every day and when krausen drops rack into a fermenter to finish it off.

 

[Screwtop]

I always open ferment................. but I kinda cheat because my fermenters are in a fridge or freezer. Fermenters are filled and the lid and airlock fitted until the yeast is pitched, then the lid is removed for one week of fermentation. The lid and airlock is then replaced for the last week of fermentation as most of the Co2 production has ceased. When using a freezer it fills with Co2 while fermenting, love them for fermenting but difficult lifting FV's in and out. Using a fridge for fermentation, door opening must be kept to a minimum as Co2 falls out when the door is opened.

Do it simply to provide a pressure free fermentation environment to assist with attenuation, and aid yeast growth. Can't say I have ever noticed a difference in flavour/aroma.

Screwy

 

[Muggus]

The risk you run with open fermenters, especially on the small scale, is keeping the CO2 cover at an adequate level.
When your beer is fermenting there should be no problem with enough CO2 to keep away nasties and oxidisation, but pre and post fermentation cover is always going to be a problem. Particularly when you're finished fermenting, if the CO2 escapes, you're not gonna have to be quick to either sparge it with more gas or transfer it to another vessel. The effects of oxidisation and wild yeasts/microbes getting to your beer are going to be more drastic in a smaller batch than a larger one.

My experience with open fermentation is from making red wines, which is a whole different ball game. Open fermenters are much more ideal for red wine ferments because you need to punch down the "cap" of skins a few times a day to get more skin contact. It's not such a huge problem when the ferment finishes with red wine because you have all of that alcohol and tannin that prevent oxidisation better than wine. Plus you can pump a bit of SO2 to kill of the bugs, which is a bit frowned upon in the brewing world. <_<
But this style of fermentation also tends to keep the yeast a bit healthier and ensures a more rigorous fermentation, which I spose would be an advantage, but i'd say the cons may outweigh the pros.

 

[flano]

i watched a video on it last night its on brewingtv and he said that you need to rouse the yeast every day and when krausen drops rack into a fermenter to finish it off.

please excuse my ignorance but what is brewingtv?

 

[kelbygreen]

please excuse my ignorance but what is brewingtv?

Link

 

[marksfish]

brewing tv is produced by two blokes from northern brewer in the us, go to google

 

[Wolfy]

I have never done any open fermentation. To me it seems that one would be having a very lax view on cleanliness. But is there any difference in the quality and complexity of the beer? Is it really just the difference in the size and dimensions of fermenter and not that the lid is open? Quite interesting none the less...I have two 50litre kegs sitting out the back of my house, that I maybe could manipulate one into being an open fermenter. But I am just still worried about sanitation.

In a home-brew situation - don't think you have to be any more lax with sanitation and cleanliness than you would usually - unless you were deliberately trying to encourage wild yeast into your brew, which - to my perspective - is not really all open fermentation is about.

If you think about the typical plastic fermentation barrels that most Australian home brewers use, in terms of beer volume vs surface area (I think) they would already be very much in the range of an open fermentation type setup (which is very different to using glass carboys as per many American home brewers for example).
The only thing missing is a free exchange of air at the top of the fermenter, which is usually limited by an airlock or cling wrap.
If you wanted to open ferment, you could easily put the open fermenter into a controlled environment like a fermenting fridge, or simply cover the top with a clean and sanitary but porous cover like a tea-towel or the like - in both of those situations you are not compromising your sanitation for the sake of having an open-air situation.

One of the differences that I see - especially related to old-English style brewing (Yorkshire squares) - is rousing the yeast on a regular basis.
However even this can be done in a controlled and sanitary situation, you could do it by opening the tap of the fermenter and cycling the fermenting beer, or a sanitised colander (or similar porous insert) inside the fermenter that you raise to mix and distribute the yeast on a regular basis, or various other methods including simply siring it with a sanitised spoon!

I actually have some new yeast on a slant in the fridge, that I'd like to try these things with, I've just not decided exactly how to go about it yet.

 

[Bribie G]

Not just ales, the Czechs -for one - use open fermenters for primary. There, and in the UK, they are more like big flat pans, a different surface to volume ratio to our Aussie 'barrels'. I once looked at big rectangular 50L food grade clip lid containers from bunnings and wondered........


:icon_offtopic: Hey this mob have stolen my idea and are selling their beer in big PET goon bottles. I'm going to sue, I tell ya.................. <_<

 

[goomboogo]

Not just ales, the Czechs -for one - use open fermenters for primary. There, and in the UK, they are more like big flat pans, a different surface to volume ratio to our Aussie 'barrels'. I once looked at big rectangular 50L food grade clip lid containers from bunnings and wondered........


:icon_offtopic: Hey this mob have stolen my idea and are selling their beer in big PET goon bottles. I'm going to sue, I tell ya.................. <_<

I like the line stating it is the best selling bear in the range.

 

[rosswill]

As Nick said, 30 years ago, the K&K was all open frmentation. Just a tea towel over the top. I don't believe I ever got an infection, but the beer was that rough, you probably wouldn't have noticed. I do recall, the yeast was very vigorous, so it would need to be a tough bug to survive the environment.