As we all know, the basic ingredients for brewing beer are malt, water, hops, and yeast. In order to cater to the local beer consumption level and reduce the cost of beer, some brewmasters prefer to add auxiliary materials such as sorghum and rice to their beer brewing recipes. Therefore, it is necessary to have a separate cereal cooker.
However, we need to control the ratio of rice or sorghum when brewing. We have heard that some customers in Rwanda heavily use local ingredients, such as malted sorghum, unmalted sorghum, bananas, and cassava, in their beer brewing, sometimes reaching up to 70% of the total ingredients. They heavily rely on rice husks to make their product work in a normal lauter tun, with barley malt making up only 30% of the recipe. They encounter difficulties during lautering.
For beer brewing, the usual ratio for adding rice or sorghum is 30% – 40%. For example, in a 1000L brewery, it is acceptable to use a maximum 500L cereal cooker.
The optimal cooking temperature for rice is between 80℃ – 85℃, while the best temperature range for activating α-amylase is 72℃ – 75℃, and β-amylase is 60℃ – 65℃.
To achieve the required enzyme temperature, we can cook the rice directly in the cooker. Then we mash the malt in the mash/lauter tun and transfer the cooked mash to the tun to mix with the malt. The temperature of the cooked mash will decrease and approach the desired temperature after mixing. This process becomes easier after several batches of brewing, and many of our customers follow this method.