Open Top Fermenter

[Seth]

I was just wondering if anyone is using open top fermenters for whiskey production? If so are there any benefits or downfalls to using them instead of closed top fermenters? Just Wondering

Thanks

Seth

[billowens]

Seth,

Only the big distillery have open fermenters and most of them are make of wood.

The new generation of whiskey distillers are coming from the micro-brewing industry.

Those brewing system have closed "jacked" fermentation tanks.

I brewed for 14 years using open tanks as has many other brewer never had a problem.

Finally, open tanks a cheaper to manufacture. Distiller's turn the beer into whiskey

and don't have the concern that a beer bottling operation has.

Bill Owens

[Denver Distiller]

While I do indeed come from brewing, I was trained on open fermenters back in the mid 90's in Germany.

Actually, Bill, you'll find this funny. In 1996 I had just finished Doemen's program, and was meeting in Bamberg with the principal of a relatively large brewhouse engineering/fabrication firm to discuss a bid for the equipment for our impending brewery. When it came time to discuss fermenters, I told him that we'd go with unitanks since we were making primarily lagers with an ale or two thrown in. He told me that you couldn't make ales in a unitank. I paused, and then told him, well, Americans have been using them for ale production for around a decade. He didn't believe me. He whispered something to a junior engineer who left the room. After a few minutes, the engineer returned with a copy of some American brewing magazine and pointed to a few brewpub pictures. The principle said "it appears your are correct". He then said, pejoratively, "that explains a lot".

He was implying that open fermentation allows for yeast harvest (and repitching) while yeast is at it's very healthiest...before it goes dormant and settles to the bottom of the tank. American microbrewers will tell you that most ale yeast is tougher than you think, and crash cooling to get the yeast to go dormant and settle into the cone of a unitank doesn't do much to effect the viability of ale yeast for the next pitch. Essentially, he was also implying that Americans don't know how to make good beer. Pretty funny.

I use open fermentation for all of our spirits. As Bill pointed out, the tanks are cheaper, and IMHO have many advantages. Yeast handling is much easier, and they are easy to clean...no PITA CIP setups.

[WineMaker]

I was just wondering if anyone is using open top fermenters for whiskey production? If so are there any benefits or downfalls to using them instead of closed top fermenters? Just Wondering

Thanks

Seth

[WineMaker]

I don't know much about fermentation of mash, but if the yeast adds flavor to the final product I would recommend Oval tanks. I sell a lot of these style tanks to wineries for the production of white wines. The oval tank has a bottom surface area about 6 times larger than a standard open or closed top fermentor of the same diameter to height ratio. This gives the fermenting liquid more exposure to the lees bed lending to a more creamy mouth feel. The other advantage is the ease of agatation.

Regards,

Dwight

[delaware_phoenix]

Sorry to bump the thread, but with open fermentation is there a concern regarding contamination from bad bugs getting control of the mash? From my reading, that is stated as the concern. Also from my reading, it would be best to have a short lag time by using a well populated yeast starter, acidify the mash to ranges that discourage bad bugs, good sanitation and perhaps some other things I can't remember right now.

Are folks really using wooden fermenters? I'd love to do that, making me feel all old school and such. Whether that produces a better product is another matter.

[Denver Distiller]

Yep, there are wooden fermenters. I can help you find them....send an email.

IMHO, there's very little worry of contamination if you clean your tanks properly, use viable yeast, and give the yeast the proper environment....just as you said.

That is, unless you want little buggies to add character to your distillate. In either case, open fermenters are a fine choice.

Contamination is only an issue if you're repitching your yeast. From what I'm told, not many distilleries are repitching. If you're not repitching and you have new, healthy yeast and a good

environment, your chances of a meaningful infection are close to zero. The fermentation is simply too fast...and unlike beer, you're vaporizing what you have fermented.