There are basically two important core steps in the brewing process of craft beer: one is maltification and the other is wort fermentation.
The wort fermentation process is mainly done by the fermenter, but how much do you know about the beer fermenter: how is the fermenter configured? What is the point of the fermentation process? What is the function of its fitting valve?
1、the basic principle of beer fermentation tank
During beer brewing, malt is prepared through a mashing system, then cooled, and then goes into a fermenter where brewer’s yeast is added to start fermentation. The traditional process is divided into pre-fermentation and post-fermentation, which are carried out in different fermentation tanks respectively.
The current popular practice is to ferment in a tank. Pre-fermentation mainly uses yeast to convert maltose in wort to alcohol (i.e. anaerobic respiration of yeast).
Post-fermentation mainly produces some flavor substances to eliminate off-flavors in the beer and promote the ripening of the beer.
2、the characteristics of beer fermentation tanks
1. It should have a strict structure.
2. Good liquid mixing characteristics.
3. The heat transfer rate of the mass transfer phase is good.
4. Equipped with reliable testing and control instruments.
5. High reliability of fermentation process.
3. Basic configuration of beer fermentation tank
1. The volume of the beer fermentation tank is determined according to customer requirements; it is generally divided into two parameters: the effective volume and the total volume. Because beer fermentation requires a certain space for the fermentation tank, the total volume is generally 1.2-1.3 times the effective volume.
2. The overall dimensions of the beer fermentation tank are generally designed flexibly according to the location of the customer, but the ratio of the basic height to the diameter is not less than 1.
3. The material of the beer fermentation tank is mainly food grade SUS304 stainless steel. If the customer has requirements, SUS316L can also be used, but the cost is much higher.
4. The polishing accuracy of the inner wall of the beer fermentation tank should not exceed 0.6um.
5. Beer fermentation tanks need insulation. Polyurethane is often used as insulation material.
6. Beer fermenters are usually designed with a lower conical shape, usually using conical 60° and 72° compression designs.
7. Cooling method of beer fermentation tank: mainly use stainless steel mel plate or water jacket cooling. In ice-water cycles, the cooling medium is typically chosen to be about 7 degrees below zero.
8. Cleaning of beer fermentation tank: mainly equipped with cleaning device, circulating cleaning with water, alkaline water or disinfectant.
9. The beer fermentation tank is provided with a top pressure manhole or a waist pressure manhole, which is convenient for observation or manual cleaning.
10. The temperature control of the beer fermentation tank is mainly detected by the PT100 temperature probe, and the solenoid valve controls the flow of ice water for automatic control.
11. The pressure control of the beer fermentation tank is mainly controlled automatically by the mechanical pressure regulating valve, and the pressure gauge is displayed.
12. Other sampling valves, butterfly valves, ice water valves, hops and other pipe fitting valves should be prepared according to process needs.
4. Function description of accessories for beer fermentation tank
1. Beer receiving valve: If you receive beer for sale directly in the fermentation tank, it is recommended to configure a beer receiving valve so that you can easily receive the beer.
2. Refrigeration system: It can accurately control the fermentation temperature of beer, reduce the error of fermentation temperature, and ensure the quality of beer brewing.
3. The access hole of the fermentation tank: it can not only increase the hops, but also facilitate everyone to observe the liquid level of the wine, and it is also convenient to manually enter the fermentation tank for manual cleaning.
4. Pressure gauge: It is mainly used to display the pressure data of the fermentation tank, which is convenient for everyone to observe the pressure in the fermentation tank.
5. Fermentation thermostat: used to adjust the fermentation temperature of beer to ensure the stability of fermentation temperature during beer fermentation.
6. Safety valve: The safety guarantee of the beer fermentation process can automatically release the pressure to prevent excessive air pressure due to human error and safety accidents.
7. Sampling valve: It is mainly used for sampling and testing of fermentation broth during beer fermentation to prevent bacterial contamination during fermentation due to sampling.
8. Liquid level gauge: If it is easy to observe, a liquid level gauge can be configured to know the amount of beer in the fermentation tank.
5. Fermentation process of beer fermentation tank
1. Beer fermentation temperature control: Controlling different fermentation temperatures has its own advantages and disadvantages. With low-temperature fermentation, the yeast produces less by-products during the fermentation process, the beer tastes better, and the foam is good, but the fermentation time is long. In high temperature fermentation, the fermentation speed of yeast is faster, the fermentation time is short, and the utilization rate of equipment is high, but more by-products are produced, and the taste of beer is worse.
2. Control of beer concentration: The change of wort concentration is affected by fermentation temperature and fermentation time. If the fermentation power is strong and the sugar reduction speed is fast, the fermentation temperature can be appropriately lowered, and the retention time at the highest temperature can be shortened. Otherwise, the fermentation temperature should be appropriately increased or the retention time at the highest temperature should be extended.
3. Control of beer fermentation time: The fermentation time mainly depends on the change of fermentation temperature. If the fermentation temperature is high, the fermentation time is short; if the fermentation temperature is high, the fermentation time is short. If the fermentation temperature is low, the fermentation time is long.
There are many types of fermenters as long as they are used in the fermentation industry. Due to different uses, they have different requirements for fermenters. Beer fermenters will also vary depending on the beer being brewed.