How Glycol Systems Work in Draft Beer Setups

If you’ve ever enjoyed a perfectly chilled pint at a bar, there’s a good chance a glycol beer cooling system was behind it. Especially in long-draw draft systems—where beer travels 25 feet or more from the keg cooler to the tap—a glycol system is essential for maintaining a consistent pour. Here's how it all works.

What Is a Glycol System?

A glycol system is a beer line cooling system that keeps beer cold as it travels from the walk-in cooler to the tap tower. It uses propylene glycol, a food-safe antifreeze, mixed with water to circulate through trunk lines—insulated bundles that also carry the beer lines. You can read more about safe glycol use in beverage systems here.

Key Components of a Glycol System

1. Glycol Power Pack (Chiller Unit)
   This is the heart of the system. It cools the glycol mixture and pumps it through the lines. Think of it like your draft system’s air conditioning unit.
2. Trunk Lines
   These are the insulated lines that run from the walk-in cooler to the tap tower. They house both the beer lines and the glycol lines in one bundled system.
3. Glycol Bath
   A reservoir inside the power pack that holds the chilled glycol-water mix.
4. Pump & Circulation Lines
   The power pack includes a pump that sends the chilled glycol through the supply line and returns it via the return line, maintaining a constant loop.

How Cooling Works

Once the power pack chills the glycol mixture, the pump pushes it through the supply line in the trunk. As the cold glycol circulates, it removes heat from the beer lines, keeping the beer at its ideal serving temperature—usually around 36–38°F. The glycol then returns to the chiller via the return line, where it gets cooled again.

This continuous cycle ensures consistent beer temperature from keg to tap, even if your system runs 100 feet or more.

Troubleshooting Glycol Loop Issues

If your beer starts pouring warm or foamy, your glycol system could be the culprit. Common issues include:

• Power pack failure or thermostat issues
• Glycol mixture imbalance (too much or too little glycol)
• Clogged or leaking trunk lines
• Pump failure or air in the loop

At CBG Draft Services we offer full diagnostics and repair for glycol systems. If you notice inconsistent pours, don’t wait—schedule a service visit to prevent further system damage or wasted product.

Keep It Cold, Keep It Consistent

Glycol systems are a must-have for long-draw setups, especially in bars, restaurants, and venues. If you're installing a new system or need help troubleshooting an existing one, CBG Draft Services is your partner in professional beer system installation and maintenance.

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