Pasteurization of Beer

What is pasteurized beer?

Pasteurization is a method of treating beer with heat to inhibit the growth of microorganisms that cause beer to spoil and extend its shelf life. The pasteurization method is named after the great French scientist Louis Pasteur, who was able to maintain beer at temperatures between 55°C and 60°C (131°F and 140°F) for a short period of time, thereby extending the beer's drinkability. Most of the world's draft beer, bottled/canned beer is produced using the pasteurization method.

Why is pasteurization so important for beer?

Pasteurization has been used for centuries to prevent food spoilage, but modern techniques were perfected by Louis Pasteur.

Pasteur initially worked in French vineyards before switching to beer brewing. In 1873, he was granted U.S. Patent No. 135,245, titled “Improvements in the Pasteurization of Beer and Ale.” In his detailed description, he outlined his findings: “I have discovered that beer produced using my new process maintains consistent quality and does not spoil or deteriorate during transportation.”

The introduction of pasteurization was a revolution for the brewing industry. At the time, beer refrigeration technology was not yet widespread, beer was prone to spoilage, and the risk of contamination in packaged beer was also high.

Pasteurization Process

• Pasteurization: Heating beer to high temperatures kills bacteria. During the brewing process, pasteurization is used to inhibit the growth of yeast that may remain in the beer after packaging.

• Canned and bottled beer: Only canned and bottled beer undergoes pasteurization. The pasteurization process is typically performed after the beer has been canned or bottled and sealed.

• Kegged beer: Beer is typically not pasteurized, so it must be stored at a temperature of 38°F to prevent secondary fermentation in the keg.

Advantages of pasteurized beer

In addition to extending the shelf life of beer, pasteurized beer has the following advantages.

Killing bacteria

One of the most important reasons for pasteurizing beer is that the process kills pathogens and bacteria that grow in beer. This ensures that the beer packaged by the company is safe for consumers and does not spoil.

Inhibiting yeast growth

Yeast remains in beer during the brewing process. If left uncontrolled, yeast may overgrow, affecting the flavor and freshness of the beer. Pasteurization can inhibit yeast growth, ensuring better beer taste.

Reduced refrigeration requirements

Pasteurized beer kegs can be stored at room temperature for 6 to 9 months. Unpasteurized beer can only be stored for approximately 45 to 60 days.

In addition, pasteurized beer can be returned to the refrigerator after opening. Unpasteurized beer cannot be returned to the refrigerator after opening and must be consumed or discarded as soon as possible.

Better scalability

Due to the longer shelf life of pasteurized beer, brewers can ship beer to more distant regions. They can reduce the cost of producing more beer and help reduce waste in the production process.

Tunnel pasteurization vs. batch pasteurization

Batch pasteurization

Batch pasteurization has long been a common pasteurization method for products such as beer and dairy products. With this pasteurization method, brewers place beer in temperature-controlled barrels.

Key advantages:

• Kills bacteria and pathogens

• Suitable for kegged beer, not bottled or canned beer

• Provides consistent pasteurization quality

Due to these advantages, pasteurization is practical for brewers looking to process kegged beer. The process is carried out before bottling and is fast, making it a convenient pasteurization method.

Tunnel-type pasteurization

Tunnel-type pasteurization is a process in which breweries pass tanks filled with beer through a stainless steel tunnel. Inside the tunnel, the machine sprays hot water onto the finished product. Tunnel-type pasteurization heats the beer to 74 degrees Celsius (140 degrees Fahrenheit) and maintains it at that temperature for a certain period of time. The machine then conveys the beer through the tunnel to another area for cooling.

Key advantages:

• Effectively inhibits yeast growth

• Suitable for breweries with national/international influence

• Low labor intensity

Due to these advantages, tunnel pasteurization is increasingly becoming the preferred pasteurization method for large craft breweries.