How is it used? What does it do?
Here's a good definition according to brewingtechniquies.com:
When using a pump to move wort from the lauter tun to the kettle, it is easy to pull liquid from the tun faster than the grain bed wants it to flow, compacting the bed and causing a stuck runoff. Aside from being a large pain, a stuck runoff can also damage the pump (magnetically coupled pumps can be damaged if run dry).
One solution to this problem is to purchase a speed controller for your pump, but these are expensive. Another option is to install a ball valve on the outlet side of a centrifugal pump to restrict flow, but ball valves can be difficult to use for fine-tuning liquid flow. A lauter grant represents another possibility.
A lauter grant is simply a vessel that collects the wort from the lauter tun. The pump is plumbed directly to the lauter grant instead of the lauter tun. Gravity gently pulls the wort from the lauter tun, thus minimizing compression of the grain bed. A float switch can be used to turn the pump on when the grant is full, thus freeing the brewer to tend to other things.
My lauter grant is an old plastic bottling bucket (see photo on page 45). A hose runs from the lauter tun to the bottom of the grant (to avoid aeration of the wort) and a pump is attached to tubing that leaves the grant through the spigot. This simple arrangement eliminates the need for an expensive pump speed controller.
I also wants to share my experience with this device (Lauter grant).
Actually I am chemical engineer and working in brewery designing company. Advantages of Lauter grant:
- It acts as buffer tank between lauter tun and wort kettle.
- It gives positive suction to transfer pump (full flow)
- Main advantage of later grant is: it avoid choking bed. as it avoid choking of bed, brewer will get maximum clear extract in less time.
- One can easily check gravity at any time.
- maximum extract with high gravity.
It have some minor disadvantages like:
- It need cleaning, Which is some what difficult operation.
- installing lauter grant may leads to increase in head lags.
One can install lauter grant between lauter ton and wort kettle, it should install before lauter tun recirculation line. Pump should have VFD (variable frequency drive) so that it can run at various RPM, so that we can control the transfer flow.
As a professional beer brewing equipment manufacturer,we would like to make a detailed clarification for the device "wort grant" here.
The wort grant is generally being installed between the lauter tun and brew kettle. Its position is generally lower than the wort level in the tank, so during lautering, the wort could flow into the wort grant automatically by gravity. The wort can then be pumped back into the lauter tun or into the brew kettle. Just meaning that the pump does not need to work on the lauter tun directly during lautering, it could better avoid compacting grain bed which may cause the lauter tun and false bottom out of shape. Now it has been standard in mostly of the brewery systems.
Wort grant is used for reducing the vacuum pressure risk during lauter process, so it can protect the false bottom from out of shape.The reason is, during lauter process, with the wort grant, the wort flows out from the lauter tun into the wort grant by gravity only（not by direct pumping). This process is gentle and easy to control.
For operation, the inlet valve of the wort grant is half open, and also adjust the pump speed accordingly to match that speed, so the wort flows are same at the inlet and outlet. So the wort flow is continuous during the whole lauter process. This is also good for pump as the pump do not need to open of close frequently.
Level balance tube: It is like a indicator and also protect the false bottom during lauter. The brewers knows if the lauter is smooth or not through checking the wort level inside the tube. When the tube is full, it means the lauter is smooth and the pressure is balanced. When the tube is not full, it means a vacuum problem.
Wort grant is a buffer tank, which place between lauter tank and kettle tank, to avoid negative pressure under the bottom of false bottom. Thus it can protect tanks in good condition. During lautering, we can adjust pump speed by VFD control, so we can keep lautering speed same with pump transfer speed, it is able to shape continuously flow. It is most economic type. Of course, we can design level sensor on wort grant, so the pump can open/close automatically at high/low level.