Craft beer brewing is a combination of science and art.
Craft beer, compared to traditional beer, is known for its carefully selected ingredients and wide range of flavors. To create a beer with pure taste, it is essential to use high-quality raw materials and excellent brewing equipment. Equally important are the brewing formula and process. So, what exactly is the process of brewing craft beer?
The brewing process can be summarized as follows: heat water and grain (and/or grain extract), boil the mixture with hops, cool the mixture, ferment it using yeast, and then carbonate it.
It sounds simple, doesn’t it? Today, we will dive deeper into each step.
10 minutes before crushing, add 5% of the malt’s weight to wet its surface. When there are no visible water droplets on the surface, it is ready to be crushed. Well-dissolved malt can be crushed slightly coarser, while poorly-dissolved malt should be crushed finer to facilitate enzymatic action.
Start stirring in the mash tun, add the crushed malt, and stir evenly. Let it rest at 37°C for 20 minutes. Then, increase the temperature gradually by 1-1.5°C per minute until it reaches 50-55°C. Stop stirring and let it rest for 40 minutes for protein decomposition. After that, start stirring again, heat the mash to 65°C, and let it rest for 70 minutes.
Heat Up to Kill the Enzymes:
Start stirring, increase the temperature to 78°C at a rate of 1-1.5°C per minute. Allow it to rest for 10 minutes, and then prepare for filtration.
In the mash tun, start stirring and pump the wort into the lauter tank. Let it settle for 10 to 15 minutes to form a natural filter layer. After the resting time, open the circulation valve and start the lauter pump. Recirculate the wort in the lauter tank for 5-10 minutes, making sure to control the flow rate at 20-30% of the maximum. Check the clarity of the wort through the sight glass. Once satisfied, close the valve, open the transfer valve to the kettle, and pump the wort into the kettle. Control the pump flow rate at 20-30% of the maximum, maintaining a balance between the filtered wort and the wort from the lauter tank. After 20 minutes of lautering, take samples to measure the original wort’s concentration.
Boil the Wort:
Open the large steam valve and start boiling the wort. Begin timing when it starts boiling. The boiling time is typically 90 minutes, but it can be extended to meet specific requirements. Add bitter and aroma hops 5 minutes and 10 minutes before the end of boiling, respectively.
After boiling, close the steam valve, open the kettle discharge valve and tangential inlet valve. Simultaneously, start the wort pump and transfer the wort into the whirlpool tank. Let it settle for 30 minutes before proceeding to the wort cooling phase.
The boiled wort is pre-cooled to approximately -6°C in a glycol water tank (using a mixture of ethanol and water). Then, it is rapidly cooled to the fermentation temperature using a heat exchanger. The fermentation temperature varies depending on the yeast strain, ranging from below 20°C to 9-15°C.
Oxygenation of Wort:
To avoid wort oxidation, oxygenation is carried out before entering the fermentation tank at a specific temperature. This is usually done using carbon stones for wort aeration.
Add Yeast and Fermentation:
Prior to transferring the wort into the fermenter, add yeast puree at a dosage of 1% of the wort.
When entering the fermenter, the wort concentration is around 9-12°P. During pre-fermentation, which lasts about 4-5 days, the wort concentration drops to approximately 4.5°P. There is no need to control the pressure in the tank, and if the environment is clean, fermentation can occur openly. Post-fermentation, mainly anaerobic, must be carried out with a sealed tank. Maintain a temperature of 12-15°C and let it ferment for 7-10 days until the pressure naturally reaches around 0.1kPa. When there is no detectable diacetyl taste, fermentation is complete.
After fermentation, gradually cool down the beer. Lower the temperature by approximately 1-0.5°C per hour until it reaches about 2°C. Be cautious not to cool it too quickly as freezing may occur in the jacket area.
Maturation: Most of the yeast settles at the bottom of the tank. Once removed, the resulting “raw beer” is pumped into a post-fermenter. Here, the remaining yeast and insoluble proteins further settle, contributing to the beer’s overall style. The maturation period varies depending on the beer variety, typically lasting between 7 and 21 days.
And that concludes the brewing process! Subsequent steps such as filtration, sterilization, and filling are carried out according to specific process requirements.