Difference between revisions of "Pasteurization in beer production"
Line 18: | Line 18: | ||
The success of pasteurization (that is, what percentage of the microorganisms are killed) is affected by both temperature and by the length of time for which the product is held at that temperature. It is a trade-off: high temperatures for short times or lower temperatures for longer times. Unfortunately, higher temperatures tend to affect the taste of the beverage. | The success of pasteurization (that is, what percentage of the microorganisms are killed) is affected by both temperature and by the length of time for which the product is held at that temperature. It is a trade-off: high temperatures for short times or lower temperatures for longer times. Unfortunately, higher temperatures tend to affect the taste of the beverage. | ||
− | The total number of PU's for a particular pasteurization | + | The total number of PU's for a particular pasteurization process for beer can be estimated from : |
+ | |||
+ | |||
+ | '''PU = t × 1.393 (T − 60)''' | ||
+ | |||
+ | where T is the temperature in degrees Celsius and t is the time in minutes at which the beer is held at that temperature. | ||
+ | |||
+ | |||
+ | '''Tunnel Pasteurisation''' | ||
+ | |||
Revision as of 21:19, 11 November 2014
Back to EFFICIENCY FINDER FOR FOOD INDUSTRY
Pasteurisation–Beer
General Description
Pasteurisation is a process of heating beer, and many other consumable products, to a temperature that will kill any living microbes without changing the chemistry or flavour. It is used by some brewers to sterilize and stabilize their product. In the brewery packaging environment, two methods of pasteurisation have evolved for beer – flash and tunnel pasteurisation.
Pasteurisation Units
One pasteurization unit (PU) is the microorganism death that occurs in a product held at 60°C (140°F) for 1 minute. It was defined in 1951 by Del Vecchio et al,1 and is employed in rating the effectiveness of pasteurization processes for beer and other products.
The number of PU's required for a particular beverage depends on several factors, such as the microorganisms it contains and even on the type of packaging. “Wild” yeasts, for example, such as occur in some types of Belgian ales, are more resistant to heat than domestic yeasts. A survey of large American breweries in 1955 found their processes averaged 14.8 PU's, with a range of 2.4 to 45.6 PU's.
The success of pasteurization (that is, what percentage of the microorganisms are killed) is affected by both temperature and by the length of time for which the product is held at that temperature. It is a trade-off: high temperatures for short times or lower temperatures for longer times. Unfortunately, higher temperatures tend to affect the taste of the beverage.
The total number of PU's for a particular pasteurization process for beer can be estimated from :
PU = t × 1.393 (T − 60)
where T is the temperature in degrees Celsius and t is the time in minutes at which the beer is held at that temperature.
Tunnel Pasteurisation
- Pasteurization in breweries
Literature: Case study: Murauer Brewery (Joints)
- Typical parameters of the process
Beer Products | Temperature [°C] | Pressure (bar) | Heat ransfer medium | Residence Time | Details | Literature |
Beer | ~70 | water | 1min | Case study: Murauer Brewery(JOINTS) |