Propylene glycol for a chiller is commonly used as a heat transfer fluid. It has a lower freezing point than water, which makes it ideal for use in cold environments. At the same time, glycol has a high boiling point, which allows it to operate at higher temperatures without evaporating.

Therefore, glycol for chiller systems acts as a cooling agent whose role is to ensure that the beer is continuously refrigerated and doesn’t get warm as it travels from a keg in the walk-in cooler to the draft beer tower through a beer line.

Breweries typically use a 35% glycol / 65% water solution.