fermeter question

[hagar681]

I have two quick questions that I think should be pretty easy for someone to answer. First when researching fermeters many use gallons or liters but some use bbl size.

How many gallons is 1 bbl? I'm thinking it's about 30 gallons and just wonder if I'm correct.

And, is there any benefit or liability to using a conical bottom fermenter or a flat bottom fermenter?

[hagar681]

FERMENTER

Excuse my typo

[Jason Parker]

Bbl stands for Brewer's Barrel, and is equal to 31 US gallons.

Cylinder-conical fermenters facilitate flocculation (settling of trub and yeast) and cropping (removal of yeast from the fermenter). If you intend to re-pitch yeast from one fermenter to the other, conical bottoms are necessary. Other considerations you may wish to consider are thermostatically controlled cooling jackets, a thermo-well, and a racking arms. Tanks configured as such are usually described as Uni-Tanks. You should be able to search the internet for every detail you care to know.

[jeffw]

Not sure conicals are necessary for yeast re-pitching. You can always top crop an open-top fermenter...

[hagar681]

Thank you for the info. As a follow up.....I plan on fermenting and distilling on the grain. Is there any drawback to using the conical for this type of distilling? They distilled on the grain where I took some classes and they used flat bottom fermenters. I wasn't sure if it was a personal preference kind of thing or if there was some advantage when distilling on the grain.

[Jason Parker]

Hi Hagar681,

I can't think of any significant advantages a conical bottom fermenter would give when fermenting on the grain. I guess it may give you more flexibility for future process changes, (like making beer!). However, I can think of a few disadvantages you may want to consider.

• The cake of yeast and trub will take up more vertical height in your fermenter, requiring the cone’s cooling jacket to keep it cool, but with little effect on the volume of beer above. In a dish-bottom fermenter, you rarely cool the dish, so only the sidewalls will provide cooling. They will act more on the beer than the yeast/trub cake, since that pile doesn’t extend so high in the tank.
  
• The yeast and trub cake is likely to pack more densely at the bottom of the cone than it would in a dish-bottom fermenter. You may need to regularly draw off some of the yeast/trub so as to prevent it from completely clogging the exit valve. I wouldn’t think you’ll have the same level of compression in a dish-bottom fermenter. So you could probably just get the flow started at the beginning, then hook up your transfer pump.
  
• Given the same footprint and vertical height, a dish-bottomed tank will give you more Bbls. Thought of another way, you can order shorter tanks (easier to move, and require less headroom) for the same number of Bbls.
  

Either way, you should be able to accomplish your desired results. It just depends on how committed you are to your process of fermenting on the grain.

Best of luck!

[Ned]

Agreed, I can't think of any major advantages with a uni-tank when fermenting on the grain and it may in fact cause draining problems as the grain packs into the cone. If you were lautering prior to fermentation the uni is a great tool, yeast will settle and can be stored under the beer for later pitches etc. Given the additional cost of the uni over a stainless tote or other flat/dished bottom tank it's hard to recommend the uni-tank. I'm using flat bottom tanks because they were less expensive at start up and they don't drain great but they work fine. You may want to consider a man-way near the bottom for clean out or follow Jason's suggestion and go with a dished bottom, it will self drain more efficiently than the flat bottom tank.