Most people are familiar with glycol as a component of antifreeze. However, not many know that glycol is also used as a refrigerant in beer chillers. In this article, we will explore what glycol is and how it is utilized in a chiller. We will also discuss the advantages of using glycol for cooling your beer. So, if you are interested in learning about glycol and how it can enhance your brewing process, keep reading!
What is Glycol?
Glycol is a colorless, odorless, and sweet-tasting (although non-caloric) fluid. It is commonly recognized as an ingredient in automotive engine antifreeze and mechanical cooling systems. Glycol possesses the ability to absorb and release large amounts of heat without affecting its temperature. This makes it ideal for refrigeration applications, such as beverage chillers.
Glycol plays a significant role as a heat transfer fluid in industrial chiller applications. Apart from providing excellent heat transfer properties, ethylene glycol also helps prevent algae growth in heat transfer equipment. Many homebrewers utilize glycol chillers in their breweries, enabling them to produce high-quality ales and lagers consistently throughout the year. But what exactly is a glycol chiller, how is it used in the brewery industry, and why would you need one?
What is a Glycol Beer Chiller?
A glycol beer chiller is a device that cools down the hot wort (the liquid extracted from mashed barley malt), and then transfers it to fermenters for yeast propagation.
Brewery chillers typically consist of two coils: copper tubing for dissipating heat from the boiled wort, and plastic tubing for carrying the cooled liquid back to the chilled water source. Glycol fluid circulates through both coils, exchanging heat with its surroundings as it moves back and forth between the two coils.
Glycol chillers are invaluable tools in commercial breweries as they enable brewers to rapidly move large volumes of beer through their processing pipelines without worrying about even the slightest increase in temperature.
However, for homebrewers, glycol chillers are primarily used for precise temperature control. Being able to adjust the wort’s temperature (the term for unfermented beer) in increments of 5 degrees or less allows for fermentation temperature control with greater accuracy. This is particularly advantageous when brewing styles like lagers, which require precise and controlled temperatures throughout fermentation and cold storage (known as lagering).
How is Glycol Used in a Chiller?
Glycol chillers enable homebrewers to quickly cool their worts to temperatures below boiling point, facilitating water condensation and starch conversion into sugar. Cooling also slows down yeast activity, providing time for accurate pitching rates and preventing potential off-flavors caused by over-pitching.
Moreover, glycol chillers allow you to remove heat from your beer-in-progress rapidly, preventing wort caramelization (burning). This is especially crucial during runoff when the hot wort first contacts the counterflow chiller. It can also be beneficial for reducing wort temperatures at the end of a long brewing day, enabling yeast pitching without having to wait for several hours. Glycol chillers help brewers save both time and water! They are also convenient as they eliminate the need for ice baths or messy “swamp coolers” by allowing for outdoor or indoor beer cooling.
Key Points About Using Glycol
Getting the water-to-glycol ratio right is essential for maintaining optimum performance of your chiller. Correctly determining the glycol concentration ratio ensures that the freezing point is significantly lowered and that your system operates smoothly. The specific ratio depends on various factors and should be discussed with an expert familiar with your equipment. Once you have the proper ratio, your chiller will function efficiently for an extended period.
Using the appropriate type of glycol for your chiller is also vital. Substituting automotive antifreeze or other random chemicals can clog the heat exchanger and disrupt the chiller’s proper operation.