Unitank vs. Dish-bottomed fermenters

[Sir Brewsalot]

So, I'm in the market to pick up 20-40 bbls of additional fermentation space, and I'm looking at some used gear.

Everything I currently have is a cone-bottomed unitank, but I see a bit of dish bottomed fermenters out there too. What are the plusses and minuses of each as you see them?

Yeast harvesting is probably the biggest change, but I've also read that flavors can be different too. Then again, I have so many other freewheeling variables I would be suprised if you could pick up difference.

Opinions, preferences, unsubstianted speculation... all welcome.

Thanks,
Scott

[Diamond Knot]

We use Grundies and conicals in our first 7 Bbl system and I would have to say hands down, no doubt about it, conicals are the way to go.
Prior to getting the conicals, we used the Grundies as primariary fermenters and it was a pain in the backside to crop yeast.

[bstreety]

Here is my advice,

Go get a massage, a nice 1 hour massage, then go home and have someone hit you in the groin with a bat. The cylindroconical tank is the massage, the flat bottomed tank is the bat.

[pbutlert]

I brewed on a system that had a mix of these tanks- dish bottoms are great for conditioning, very poor for fermentation. Yeast harvesting is inconsistent at best, and there were noticable flavor changes between tanks. The previous post pretty much sums it up. Investing the extra time and money will prevent headaches for years to come!

[Sir Brewsalot]

Thanks for the input everyone. I was thinking of just limiting my yeast harvesting from the conicals I currently have, but I'm not sure my fermenting schedule would permit it every time. Even then, flavor variations don't sound too good to me either.

Sounds like the extra cost will be money well spent. So I suppose now the only question is, shiatsu or swedish?

Much appreciated.
Scott

[tarmadilo]

I worked at a micro that started out with open-top dished-bottom fermenters (and separate aging tanks), and we expanded into unitanks. After a few years, we then built a new brewery, and it was all unitanks, all the time!

Just so much simpler to harvest yeast, drain yeast, ferment AND age the beer. Given a choice, I'd never use anything else!

Cheers, Tim

[GlacierBrewing]

Hi Scott,
My two cents:
Try Hawaiian Lomi-Lomi massage!

[Greenbrewmonkey]

Hello all!

Sorry to have to do this but...
Open, flat bottomed fermenters, with a true top cropping yeast, using secondary conditioning vessels make the best beer! Especially if you are going for a bright, unfiltered beer.

They may be more work, but at the end of the day, its all about the beer. Right?

But if your only choices are conical vs dish, go with the conical. The other posts are right on about that.

Aloha,
Ron
Jolly Pumpkin Artisan Ales

[damoller]

Hello all!

Sorry to have to do this but...
Open, flat bottomed fermenters, with a true top cropping yeast, using secondary conditioning vessels make the best beer! Especially if you are going for a bright, unfiltered beer.

They may be more work, but at the end of the day, its all about the beer. Right?

But if your only choices are conical vs dish, go with the conical. The other posts are right on about that.

Aloha,
Ron
Jolly Pumpkin Artisan Ales

I agrre 100% with Jolly Pumpkin. A dish bottom is too much problem to ferment in and should not be used!
#1 Flat Bottom (mild slope to outlet)
#2 Conical (still a pain to use with floculant yeasts which produce the most flavor!)
# Dish bottom (the worst of both worlds!)

[Moonlight]

Flavors will be different, how much is unknown-they may even be better, esp. less diacetyl. I wouldn't plan on aging in a dish bottom fermenter full of yeast as you will have autolysis or yeast flavors. If racking into aging, it doesn't matter. Harvesting yeast from the conicals and pitching into the dishes shold work just fine. This would lessen the bat to more like a stick. The massage is more comfortable but one can't always afford it.