brewing half batches

[billk]

I have a 10 bbl system and am thinking of brewing some of my seasonals in half batches to turn them over faster. If I shut down the top half of my steam jacket in my kettle I think I won't have a problem there. My concern is with maintaining a constant temp in my fermenter. If I have 5 bbls of wort, only about the top 20-30% of it will be in the glycol lined portion of the fermentor. Is this enough to maintain a reasonably constant temp through out the fermentation and subsequent lowering?

Thanks in advance for any input.
Bill

[Ted Briggs]

I have always had at least one fermentor w/ 2 jackets for this reason and also for croping up yeast. A good idia for brewery design!
I figgure' that as long as your temp probe hits liquid it should be ok. Hot rises so as you cool the top, covection currents should do the rest. It may not crash as fast but it should get there.

[Sir Brewsalot]

You'd also have the task of purging your brite tank w/ CO2 to keep it away from oxygen, but you probably already knew that.

S

[jipjanneke]

There was another thread which did cover some relevent related issues:

http://www.probrewer.com/vbulletin/s...&threadid=1256

There may be something useful for you there as well...

[MikeJordan]

I would guess that you will have some problems maintaining uniform temperature during fermentation and conditioning. I have noticed this in the past when emptying small tanks that are half filled and barely in contact with glycol jackets. Sometimes convection currents are weak and vary with temp. and density. The temp. probe may give various readings and you'll usually see stratification leading to potentially troublesome filtrations. Watch the temp. during transfer to ruh and maybe check cell count at start and midway through transfer. This should give you an idea about what is happening inside your FV. That being said all equipment is different and you may see no problems and have no off-flavors from fermentation. Good luck!

[BigWilley]

You could minimize problems by using a temp. tolerant strain like American Ale. Also what I have done to check the temp in the cone is when I pull off trub and the first bit of yeast I will stick a good thermometer in to check. You could do this during the ferment and if you have a sample valve low enough check it to. I regularly brew 10 bbl batches on a 15 bbl system with no problems. You may have a problem getting a good boil with only the bottom jacket, I know I would, so check that out with some water first.