from wort to glass in a single (unitank) vessel?

[Vendetta]

Basically, I am wondering about the pros and cons of fermenting in a unitank, and then serving directly from it in a brewpub. Naturally, some things (filtration etc) only become possible if you're willing to rack to another tank, but for the purpose of this post, I am not.

My initial list of concerns with this process :

-fermentation or other debris not removed by fining (autolysis and chunks)
-efficacy of serving standpipes with regard to separation / passage of debris
-pressure requirements, and the expense of ASME tanks

From my limited perspective, this approach seems like fewer vessels, less space required, less oxygen pickup, and generally less labor. So why does nobody seem to do this (tho I understand it's not uncommon to bottle from a uni) ? I'm looking for more compelling reasons not to do it... I know I must be overlooking something.

Thanks,
Chris
Vendetta Brewing

[lhall]

I guess it could be done. But you are tying up valuable fermenter space by serving it from the unitank.

[South County]

I don't see how you can practically and cost effectively do it. What you "gain" in floor space and savings you'll loose in potential sales.

Scencario: Brewpub, Ales, 2-3 weeks

4 Uni-Tanks: all 4 have beer in them and are being served from. They are now close to being empty, what do run a brew into now? Your only option is to have 2 full and two fermenting which now limits you to only having 2 styles on tap or keg it off but that still requires storage space.

Either way you looking a 2 tanks per style (FV & BBT) to keep a regular rotation
and steady revenue. I can't imagine any brewpub having any less than 4 styles on tap which would require 8 tanks total.

[Vendetta]

I don't plan on only having 4 tanks!

Guys, I appreciate your immediate reaction, but my plan does not involve tying up a uni at the opportunity cost of a new brew. Rather, it involves the flexibility of having as many vessels as one ordinarily would... just that they would all (8-12 of them) be unis instead of single purpose vessels which necessitate scheduling. Obviously, kegging the last few bbls would help here as well.

Cheers,
Chris

[Larry Horwitz]

Bling

Mostly it's a cost issue....FVs are WAAAAY more expensive than brights...in the long run it's far more cost effective to use a different tank to serve your beer.

use your extra $$$ to buy an automated keg cleaner. You'll thank me.

[South County]

Guys, I appreciate your immediate reaction, but my plan does not involve tying up a uni at the opportunity cost of a new brew. Rather, it involves the flexibility of having as many vessels as one ordinarily would... just that they would all (8-12 of them) be unis instead of single purpose vessels which necessitate scheduling. Obviously, kegging the last few bbls would help here as well.

Cheers,
Chris

Sorry...Just when you said

From my limited perspective, this approach seems like fewer vessels, less space required, less oxygen pickup, and generally less labor.

That to me means less tanks.

If you had 8-12 tanks and they all were uni's and you have the cash go for it.

[william.heinric]

Long-Term Costs of Uni's

Just a thought here...

Wouldn't the long-run cost differential between a strictly unitank system and a traditional mixed vessel system approach zero, or perhaps become negative? Consider:

S(m) - S(u) = C(diff)

where S(m) is the cost of using a mixed system, S(u) is the cost of using a strictly unitank system, and C(diff) is the cost differential between the two. We begin by assuming that the short term is a single batch, and that both systems can produce the same quantity, then:

S(m) = [P(m)/V] + L + W - QC
S(u) = [P(u)/V] + L + W - QC

where P(m) is the actual market price of the tanks in a mixed system, P(u) is the market price of the tanks in a uni system, V is volume of beer, L is labor, W is waste, and QC is quality and related intangibles. Because the divisor V is small in a single batch, the formula is dominated by P(m)<P(u), and the short term costs of a unitank system compared to a mixed system {C(diff)} are very high. But, if we expand the S(m) to S(m;1,2,...,n), which takes into account the long-term number of batches to be put through the system, and do the same for S(u;1,2,...,n), then C(diff) becomes progressively smaller the longer the system is in use.

Now, if we differentiate L, W, and QC into X(m,u;1,2,...,n) as a format, we can show that unitanks have a negative cost. Allow me throw out a few more assumptions about uni's:

There are lower labor costs for uni's in the short- and long-terms, such that L(m)>L(u), and L(m;1,2,...,n)>L(u;1,2,...,n).

There is less wasted product from a unitank, such that W(m)>W(u) and W(m;1,2,...,n)>W(u;1,2,...,n).

There is less surface contact of the beer with other surfaces or oxygen, such that QC(m)<QC(u) and QC(m;1,2,...,n)<QC(u;1,2,...,n).

If these assumptions hold true, then the long run cost differential of using a strictly unitank system is negative compared to a mixed system. That leaves the real question: How long with a unitank system last?

I don't know, maybe Chris is on to something with this idea. If its less expensive and makes better beer, that's pretty hard to argue with.

Happy Brewing,
Bill

[Vendetta]

Just &quot;wow.&quot;

Bill, that was quite a showstopper. You said all the things I wasn't smart enough to say, right down to the transfer losses and the "intangibles" (a category that is heavily weighted in my personal "equation" for no scientific or quantifiable reason at all). But can we get beyond the initial outlay, and delve into the other reasons this isn't a good idea? For the purpose of this thread, I'd like to see this boil down to a quality issue (and O2 is a pretty big one, I'm told).

Cheers,
Chris

[beermkr]

Wow that was a lot of math.

I think you can do this without ASME certified tanks. Using a Beer pump such as Perlick sells you can keep your tanks at normal carbonating pressures and pump it as far as you need.

I like the thought of 8 tanks 4 taps or something along those lines. Additionally the kegging thing helps except that you have the issue of cold storage. With just the fermentors you could get away with no serving walkin.

Mike Pensinger

[sbradt]

Taxes?

One thing that no one has mentioned so far is tax determination. I don't know if the tax man is going to accept a unitank as a tax determination tank.

[jwalts]

No matter how thoroughly I dump yeast from an FV, I'm always surprised at how much solid crap goes down the drain when I dump the heads and tails of a tank-to-tank transfer. That and keeping the tap lines cold all the way to the FVs are two quality issues that come to mind immediately.

Joe

[Vendetta]

Heads N' Tails

Joe, I do agree about the chunky stuff in the heads and tails, but is this a problem that careful dumping and racking (serving in this case) can work around? Presumably, I would instruct bartenders to stop serving from the vessel when even a hint of crud found its way into a glass. I guess it's a matter of how substantial the flavor contribution of that remaining stuff is over the life of the beer.

As for keeping the beer cold in the lines, that's an issue I would want to address no matter what the tank setup is. Insulation and glycol on serving lines are a foregone conclusion in my opinion.

[Joe Brewer]

It would work but...

I think this would work. Obviously you'd be drawing the beer from a racking port, not the bottom of the tank so most chunks could be avoided. You'd need to shoot the newly settled trub out of the bottom of the tank every couple of days. On the negative side; as has been pointed out the initial cost of the tanks would be an issue.
I don't think that your beer would be noticeably better due to less oxygen pickup. You'd have to have really lax cellaring standards or have the beer sit in the tank for several months to get significant oxidation in a simple FV>serving tank system