Open Fermentation

[Thirsty Boy]

Well I did it.

I currently have about 7.5 gallons of a dunkle weizen fermenting away in the basement. I'm taking pictures and need to know how to post them. It's completely open sitting on a pillar of concrete blocks at 4 blocks high. No legged critters can get into it and from what I've ready anything that can fly won't land in it bc it would be overcome by the CO2 coming off. We'll see.

I pitched approx 200ml of super thick, creamy white 3068 yeast (i'm talking sludge) that I grew up on a stir plate for about 2 weeks.

After about 12 hours I noticed the "hop drive" and new colonies forming on the surface. I sanitized my wife's wire sieve from the kitchen in some Idophor and pulled all of it off. Right now I'm about 36 hours into it and have almost 5 inches of krausen on top. I plan on harvesting the yeast tonight.

I'll post more details later as they come.

Mate - open fermentation only makes a difference because of the lack of head pressure and maybe the shape of the fermentor - soak a bath towel in starsan and drape it over the top of that fermentor, or if you are using a carboy - a handkerchief. Just to stop bugs landing in it by accident and bacteria falling into it.

[pmanz]

That's why I chose to use my boil kettle vs. a carboy. The taller shape of a conical or carboy is supposed to affect the way the yeast acts. The kettle allowed me to have a shallower vessel. I had thought about possibly hanging something over part of it but wanted ti to be able to breathe as much as possible.

I know the room looks pretty skeevy but before I ever start a brew day down there I ope the windows and use one of those chemical mixers you can put on a hose for weed killer and blast the walls and floor of the room with a mix of bleach and water. Then I hose it all down with 180˚ water out of my heating system. It all gets pumped out by my sump-pump. It works rather well. A coat of masonry paint will do wonders whenever I get around to it.

[Thirsty Boy]

Yeah, thats the "shape" of the fermentor thing and it makes a big difference when your fermentors are 5 stories tall, not so much when they are two feet tall... but in either case, you have taken care of it by using your brew pot.

That doesn't cover the "open" thing though. You are acheiving nothing whatsover by leaving the thing uncovered, except the chance that you will brew a really intersting spontaneously innoculated lambic... chances aren't high that it will be interesting in a good way though.

Those "open" fermentors you are talking just aren't really that open... either (as a few others have said, they are in a very clean sealed room, or for things like yorkshire squares, burton unions .. the english "open" fermntors.. they all have lids or are closed cubes... they just have an unrestricted opening to the atmosphere somewhere.

With a nice cloth over the top... yoe still have a nice large surface area, you still have free and easy gas exchange, no head pressure.... in short, all the things that are supposed to make open fermentation different to closed. But you dont have the chance of a fly dropping in for a swim.

Of course, you'll do what you think is best, but I think the risk you are taking by ferementing that thing without a cover... has no benefit as payback, thats all.