11 Tips for Using Propylene Glycol Coolant in Beer Brewing

When you’re brewing and using food-grade propylene glycol coolant, these are the things you need to know:

1. Double-check you’re getting food grade propylene glycol USP (United States Pharmacopeia) and not its toxic cousin ethylene glycol or the industrial version of propylene glycol (which is not suitable for recirculation systems and could damage brewing equipment). The FDA says the food-grade version is safe and is what you should use for brewing.
2. Get your ratio right. A common standard for many breweries is to use a mix that is 35% to 40% glycol. This ratio cools fast enough for most brewing and serving needs. 
3. Don’t overcool. This stuff works great at getting things cold, and if it’s too concentrated, you run the risk of frozen or burst lines. A good rule of thumb is to have a freezing level of your glycol/water solution 20 to 25 degrees Fahrenheit below your chiller system. 
4. Use glycol for wort production. It can accomplish the rapid cooling you need and give proteins a thermal shock in the process so you don’t get oxidative damage. You can pass the wort through a single- or double-stage plate heat exchanger that has a glycol/water mix on the water circuit. Use a double-walled food-grade heat exchanger to further ensure against contamination.
5. Use glycol for fermentation. It’s great at offsetting the heat that the yeast creates as it gobbles up the sugars in your batch. 
6. Use glycol in packaging. You already are going to have glycol on hand; why not make the most of it! A chilled glycol fan coil can be added to a chiller, and you can create a cold storage room pretty easily. This may lower installation costs versus other refrigerant options.
7. Use glycol for long-draw lines. If you’re serving beer on-site, and the trunk line from the kegs to the taps is a significant length, you don’t want to be pouring people room-temperature pints. Make sure your lines are insulated well if you build them yourself. 
8. Keep your setup simple. You want to limit places where propylene glycol can build up, like joints and connectors.
9. Place coolant systems as close to your tanks as you can to reduce installation costs and cut down on transit lines.
10. Use a refractometer to measure the amount of glycol in your mix. Even though propylene glycol does not contain sugars, it affects the refractive index.
11. Replace your glycol when needed. Propylene glycol is good for two years from when it is manufactured. Keeping it out of direct sunlight in sealed drums or totes is best.

Glycol can be a brewmaster’s secret weapon for temperature control and has tons of great uses. If you’ll be using it in large quantities, make sure you buy in bulk and get either 55-gallon drums or 330-gallon totes. You can also save more by buying from Keller-Heartt because we don’t charge delivery fees on orders. Free shipping—cheers to that! Happy brewing!