Generally speaking, the whole refilling process takes about 90-120 minutes. Most breweries are now equipped with grain rakes, which will help speed up the refilling process.
Once the spent grain appears in the wort, the first wort refill should be stopped and hot water for the refill should be added. Today’s fermenters use a spring ring to allow the water to spray evenly onto the grain bed. The duration is no more than 10 minutes at a time.
If the turbidity value rises, the grain rake should rise, or it should fall. If the differential pressure rises, the rake should go down to loosen the grain bed. But this will cause the turbidity value to rise again, so the whole process should start again.
Once the concentration of the blended wort is reached, the filling can be stopped. This concentration is usually lower than the final wort concentration by 1.0-1.5 plato. The spraying process should not be overdone, otherwise some bad ingredients such as silicates and bitterness will enter the wort and affect the taste of the beer. In addition, oversparging will require more energy to boil, which is uneconomical.
There are many innovative ways to prevent waste with spent cereal. Please check the following.
1) Waste grains can be used in agriculture, for example, in the form of compost to fertilize fields, gardens or urban greenhouses. Thus providing people with nutritious natural food. Waste grain compost can also be used as a growing medium for mushrooms.
2) Waste grains can be fed to animals such as chickens, sheep, llamas and pigs, which in turn provide eggs, milk, wool and meat. And it is easy to find a poultry plant in the area.
3) Many craft breweries also reuse their spent grain in their own kitchens to cook up immediately satisfying delicacies such as baked bread. Eggs can also be used to make desserts, quiches and breakfast dishes.
4) There are also many revolutionary uses for spent grains, such as powering entire breweries with them.
For example, some breweries have developed a first-of-its-kind biomass steam boiler, and the boiler then converts the spent grain into process steam for the brewing process.
At the same time, it will reduce the use of fuel oil, making it more environmentally friendly.