What Temperature Should I set my Chiller to?

On the face of it this seems like an easy question to answer, but the more you look into it the more opaque it can become.  There are a handful of things to think about when setting your chiller.  The first thing I would think about is the fact that all refrigeration cycles operate more efficiently as the set temperature is increased.  For this reason, you wouldn’t want to set your chiller as low as it will go because you will cause your chiller to run less efficiently.  Another reason you don’t want to set your chiller too low is based around the freezing point of whatever your product may be.  We have seen beer freeze to the inside of a fermenter because of the glycol temperature being set too low.  I have also heard of brewers breaking the float valve on the inside of their Cold Liquor Tank (CLT) because a large piece of ice came loose and sheared it off.  So for these two reasons, I will recommend customers to set their chiller as high as possible while still being able to “get the job done.”

What does it take to “get the job done”?

In short, it matters what the job is.  In a brewery you will likely see ales fermenting from 64°F up to 72°F and lagers fermenting at 50°F to 56°F.  However, in a brewery maintaining fermentation temps isn’t the only thing the chiller has to do.  Often brewers will cold crash their product down to 32°F to 34°F.  For this reason we often recommend brewers set their chillers at 26°F to 28°F to facilitate the cold crash function as well as to maintain brite tanks that operate at 32° to 34°F as well.

In a distillery you will often see fermentations take place around 80°F+ and there is no need for cold crashing.  For this reason we can often set distillery chillers as high as 60°F to 70°F and take advantage of running more efficiently at higher temperatures!

Another large cooling load in a lot of breweries is the wort heat exchanger.  If you are using glycol in a two stage heat exchanger you will be adding a large load to your chiller.  The lowest that wort out of the heat exchanger will be going to is ~50°F if you are making lagers.  As we stated before though, you will likely have your brewery chiller set to 26°F or so, which is overkill for this service.  You might ask then, why not turn up the chiller when you are knocking out?  That isnt a bad idea if your facility can manage that!  If you can turn off all of your crashing tanks and brite tanks for the 45 minutes or so it takes to knock out your wort the chiller can run at a higher temperature, more efficiently, without any negative side effects.  If you can’t do that then you will have to use a lower temperature glycol to manage the cooling and deal with the lower efficiency ratings.

Wineries are similar to distilleries in that there is generally no cold crash requirement, so the minimum temperature the chiller has to maintain is usually set by fermentation temps, 50°F to 58°F for whites and 68°F to 78°F for reds.  So in a winery you can usually get away with setting your chiller at 45°F if you are fermenting whites and up to 60°F if you are fermenting reds.

Looking at all of this information, you might think, “I’m more confused now than when I started!”  That’s fine, feel free to reach out to one of us here at G&D and we can help you with the appropriate set temperature for your chiller based on our 26+ years of experience!