Important Configuration of Lauter Tank
1. The lauter screen (also known as false bottom or lauter filter) is positioned 20mm above the bottom of the lauter tank. The gap ratio is typically 10%-30%. Each gap resembles an inverted ‘V’ shape, with a width of 0.7mm at the lowest point and 0.1mm at the top point.
2. In an industrial brewery, there are multiple wort outlets at the bottom of the lauter tun. These branch wort outlets converge into a main wort outlet located in the center. This setup is referred to as wort collecting rings. The wort outlet tube should have a conical or arched shape.
This design minimizes the risk of over-pumping or vacuum conditions and effectively maintains a reasonable lauter speed. Nowadays, some brewmasters prefer to incorporate this design in their microbrewery equipment as it simplifies operation and reduces monitoring intensity. Our suggestion is to consider implementing this configuration for breweries larger than 1000L. Additionally, the wort collecting rings are usually used in conjunction with a wort grant tank.
3. Rake: The rake plays a crucial role in accelerating the lauter process and ensuring wort quality.
Most of the time, after the initial lauter recirculation, the grain bed becomes tightly packed. Therefore, the rake is necessary to loosen the grain bed and expedite wort flow.
Furthermore, during sparging, the rake improves the contact between water and wort and creates new wort flow paths. This results in a faster lauter process and more thorough sparging.
Solutions to Relieve Lauter Blocking
During the lautering process, there might be instances where the filter speed is extremely slow or even stops completely. This significantly prolongs the lauter time and affects both wort quality and the normal brewing process. The main reasons for this situation include poor grain quality, inadequate mashing results leading to a high viscosity and unfavorable sugar composition, or operational errors during lauter. Here are some immediate solutions:
1. Stop the lauter and activate the rake to loosen the grain bed.
2. Larger lauter tanks are typically equipped with anti-rinser rings. In such cases, hot water (75-78℃) can be sprayed from the bottom to aid in loosening. If the lauter speed still does not improve, anti-rinse water can be used while simultaneously activating the rake for 2-4 minutes of agitation. If necessary, increase the raking speed to disrupt the existing grain bed, then allow the wort to settle for 5-10 minutes to form a new grain bed before restarting the lauter. It is also important to insulate the lauter and ensure that the sparge water temperature is not too low.
3. Slow down the pump/lauter speed to avoid creating a vacuum.