The Role of Cooling And Glycol Systems in Craft Breweries

The cooling and glycol system is one of the most critical pieces of equipment in a brewery. While the cooling system isn't directly connected to the milling, mashing, lautering, and boiling processes, heat from these processes ultimately needs to be removed through it. Without proper cooling, beer can spoil, developing off-flavors, a cloudy appearance, and other defects.

Comparison of Cooling System Types

Direct Expansion (DX) Cooling System

• How it works: Circulates refrigerant through a heat exchanger to cool beer.

• Advantages: Cost-effective and easy to maintain.

• Disadvantages: Less efficient for large breweries.

• Suitable for: Small craft breweries or startups with limited budgets.

Glycol Cooling System

• How it works: A mixture of water and ethylene glycol is circulated through a pipe network to cool beer.

• Advantages: More efficient than DX systems and can handle the needs of large breweries.

• Disadvantages: Higher initial investment.

• Suitable for: Medium to large beer production facilities.

Air Cooling System

• How it works: Ambient air is used to cool beer through a heat exchanger.

• Advantages: Simple system, low cost.

• Disadvantages: Less efficient in hot and humid environments.

• Suitable for: Small breweries in cool climates.

Glycol System Details

Glycol Chiller Function

A glycol chiller is a compact refrigeration unit specifically designed to cool beer and maintain its ideal temperature, ensuring consistent temperature throughout its journey from the cold room to the beer tower.

Choosing a Glycol Type

• Food-grade Propylene Glycol: Completely non-toxic, preferred by the food industry, with a freezing point as low as -59°C (-74.2°F)

• Ethylene Glycol: Used in automotive antifreeze, not suitable for food applications

• Mixing Ratio: A 35%-40% propylene glycol to water ratio is optimal for most applications

Glycol System Advantages

• Long-Distance Delivery: Supports beer delivery distances up to 450 feet (approximately 137 meters)

• Design Flexibility: Supports a variety of beer tower designs

• Cost Savings: Reduces pouring costs and improves operational efficiency

• System Protection: Extends cooler life and reduces vibration and noise

Wort Cooling Technology

Cold Liquid Tank (CLT) with Single-Stage Wort Heat Exchanger

• CLT Construction: Stainless steel tank with air-conditioning jacket or external heat exchanger

• Operating Temperature: Cooling water maintained at approximately 35°F (1.7°C)

• Cooling Ratio: 1:1 pumped exchange with wort

Two-Stage Cooling Process

• ‌First Stage‌: Using tap water at a 1:1 ratio to remove most of the heat, cooling the wort from boiling point to a range of 7-10°F (-13.3 to -12.2°C).‌

• Second Stage‌: Using cooling glycol to remove the remaining heat, bringing the wort to the ideal fermentation temperature.

Ethylene glycol usage precautions

Temperature control: The proper temperature range and glycol/water ratio must be maintained; failure to do so may cause the system to freeze.

Safety risks: Ethylene glycol can be flammable, so manufacturer safety regulations must be strictly followed.

Cost considerations: Ethylene glycol is more expensive than other coolants.

Maintenance requirements: Regular inspection and maintenance of the system's status are required.