Normally for commercial brewery, a two-stages heat exchanger that uses a combination of cold liquor, chilled glycol and city water to cool the wort, this is happen in most of the countries especially where the temperature is hot, and are typically found at breweries that brew a lot and have simply grown beyond the designed capacity of the brewhouse. Some also uses ground water and single stage exchanger with cold liquor only to cool wort, this is more often used in Europe and North America countries, which is more energy saving.
The optimum temperature range for yeast fermentation is between 90˚F-95˚F (32˚C-35˚C). Every degree above this range depresses fermentation. While elevated temperature is problematic in all phases of ethanol production, it is specifically hazardous during the later stages of fermentation.
Yes, the glycol water is sufficient to cool tanks. As the refrigerator contains a small ethylene glycol water tank, which can cool the fermenters and bright tanks through its dimpled cooling jacket. The jacket of the fermenter and the glycol water tank form a closed cycle, which can also exchange heat with the refrigerator to achieve cooling purpose. But if the number of fermeter and bright tank is a lot, and the temperature of the installation country is hot, it’s also need to consider a separated glycol water tank.
1. Cold Liquor Tank (CLT) and a Single-Stage Wort Heat Exchanger
The CLT is typically a stainless steel water tank with cooling jackets. The CLT is filled with water that is chilled by glycol chiller, between brewing cycles to a temperature around 35 F. This cold water is then pumped through the wort exchanger, cooling the wort from post boil temperature to the desired fermentation temperature. The exiting water, (now 140-160 F) is transferred to the hot liquor tank to be utilized for the next batch of beer. The CLT is often sized to hold enough cold water to service a typical 24-hour brewing cycle. For example, if you have a 10bbl brewhouse, and will typically brew two times per day, the CLT would be sized at 20bbl.
2. Two-Stage Cooling using City Water and Chilled Glycol
Two-stage wort exchanger cools the wort in two steps:
- Utilizes city water, removing as much heat as possible. Depending on heat exchanger efficiency, wort will exit the first stage within 7-10 F of your entering water temperature.
- Transfers the remaining heat to chilled glycol and exits at desired fermentation temperature.
Different beer should have different fermentation temperature, normal ale fermentation temperatures range from 68 to 72 °F (20 to 22 °C) and lager fermentation temperatures from 45 to 55 °F (7 to 13 °C). Also keep in mind that the heat generated by an active fermentation can warm a typical 5-gallon (19-L) batch of beer by 10 to 15 degrees Fahrenheit (5.5 to 8.3 degrees Celsius).
The less automated the system, the more you need to do yourself, this could be adding grains, adding hops, transfering beer into fermenter, or filling beer in keg or bottle, with automated systems can reduce a lot of labor during the brewing process, and easily to realize scaled beer production.
Automatic control brings a lot of convenience, such as fix brewing formula parameters, control the feeding process, and will automatically adjust the water temperature, water speed, off-site monitoring and remote access and easy for brewery expansion in future. For more about automatic control system, you can click here.