Glycol Temps, whats yours?

[dhoyt]

I'm curious if there are any downsides to keeping glycol temps in higher than normal ranges like 55°F. I am thinking about this for a few reasons but one of them is when I am not fermenting beer there isn't really a need to have the temps down at 28 °F. My concern is if higher temps would assist in nasties growing in the mixture. I have been told glycol itself can help inhibit bacterial growth but I didn't know if anyone regularly kept there chillers at high temps or even just off when not in use. Another reason is I am working on a little fermentation automation and keeping the glycol temps closer to fermentation temp setpoint may help smooth out control and allow for tighter deadland and deviation from setpoint.

Cheers!

 

[danb35]

I shut off my chiller when I'm not fermenting or planning to within the next day or two (i.e., if there's a day or two between batches, I'll leave it on). Haven't noticed any ill effects, but I've only had it since earlier this year.

 

[pvpeacock]

Ditto Danb35

 

[danb35]

Oh, and on the temp question, I'm set at -2C.

 

[SBENCIV]

My glycol chiller is a converted dorm fridge. When I ferment, I keep my glycol at around 22 - 24f. Once done, and if I'm not planning on fermenting for a number of weeks, I will unplug the fridge and prop the door open - this allows air flow into and out of the fridge, which also inhibits mold growing inside the fridge itself. I have never had any issues. As a matter of fact, I have to top off my glycol mix every now and then and in the 3 years I've been running it, I have never changed it out. It looks as new as the day I poured it in.

 

[shoengine]

I use a Ss 1/5hp chiller and I only leave it on about half of the time, the rest of the time it is either idle, or right now I have an aquarium heater in it set to 80° F since my garage is in the 40s and I need to keep my beer warm. Been about two years and the gylcol still smells and looks fine.

 

[dhoyt]

Awesome, thanks gents!

Cheers!!

 

[bailey mountain brewer]

I keep mine at 28f year round, I just make sure I'm always fermenting something that way it's always being used.

 

[cfrazier77]

I keep my glycol 15 to 10 degrees below my target fermentation temp when fermenting. So, 50s often. When I am not brewing I turn it off to save electricity. I have never had a problem with my glycol.

 

[dhoyt]

I keep my glycol 15 to 10 degrees below my target fermentation temp when fermenting. So, 50s often. When I am not brewing I turn it off to save electricity. I have never had a problem with my glycol.

This is what I'm curious about really. I'd like to program the chiller to dynamically change the setpoint on fermentor setpoint. I heard some people doing what your doing here but didn't know if there was an issue with the glycol getting gross.

 

[cfrazier77]

This is what I'm curious about really. I'd like to program the chiller to dynamically change the setpoint on fermentor setpoint. I heard some people doing what your doing here but didn't know if there was an issue with the glycol getting gross.

I just recently changed out my glycol, 4 gallons, and it was 2 to 3 years old with no nasties. It is in a commercial unit, micromatic, and the gycol tank just has a cover over it, it is not sealed. I changed the fluid because I had more and wanted to get rid of it. I use RV winterization antifreeze. I use the prestone 100% human safe proprolean glycol that is $7 at Walmart per gallon and it takes 1.5 gallons of glycol to 2.5 of water.

This works for me in my situation, I can't say it would work the same for your situation with full confidence.

 

[Mr. Vern]

Propylene glycol is stable for at least two years. I’m guessing it is probably good for 3 to 5. No need to worry about bacteria and other nasties because you should be running a concentration above 30% glycol. You will have water evaporation because the tank is not sealed (thermal expansion needs to vent), you can top off water as needed. Dwyer makes some pretty neat temperature controllers with serial communication FWIW.

“With concentrations at or above 20%, both Ethylene and Propylene Glycol inhibit the growth and proliferation of most microbes and fungi. The reduced surface tension in the glycol solution interrupts the cell walls of the bacteria, resulting in an environment that will not support bacterial growth.”