False Bottom or Screen?
I recently decided to see how a screen-based lautering system compares to a system using a false bottom. In the past, I have always used a system consisting of a Phil's Phalse Bottom in a plastic bucket, with reasonable results. For this test, I used a piece of tubular stainless screen which is mareted by Al Korzonas as the "SureScreen". (If I'm not mistaken, the SureScreen is basically the same thing as the Schmidling EZ-Masher, just sold under a different name.)
Modifying the Lauter Tun
Here's a picture of the interior of my original lauter tun, complete with Phil's Phalse bottom:
Anyhow, I took the SureScreen, and stuck a short piece of rigid plastic tubing (cut from a plastic racking cane) in the end, like this:
(You can't really tell from the above picture, but the plastic tubing extends about 3/4" into the SureScreen. It's a fairly snug fit, and seemed secure enough without a hose clamp.)
Then, I removed the false bottom from my lauter tun, and pulled the plastic hose thru the wall of the bucket until only a couple of inches of it remained inside. Then, I simply jammed the other end of the rigid plastic tubing (with SureScreen attached) into the open end of the hose, like this:
The entire process took just a few minutes. The most time-consuming part was cutting the piece of plastic tubing, and smoothing the rough edges with a file...
Results
I brewed a pair of batches with the modified lauter tun. Everything went smoothly. My runoff cleared quickly, and there were no problems during the sparge. The sparge actually went somewhat faster than it used to; for some reason, the wort seemed to flow more freely with the screen-based system, even though I set the plastic shutoff clamp to the same number of "clicks" I always use.
In spite of the faster sparge, my extraction efficiency increased somewhat -- I had been getting in the 65-70% range, but got approximately 75% efficiency on both batches lautered with the screen.
I plan to use this system again, to see if the extraction numbers remain consistent.
Update, March 2000
After using the screen-based lauter tun on a number of batches, I think I will be sticking with it. Extraction efficiency seems to be consistently a few points higher than with the false bottom, and fewer grain particles make it through the screen. Fewer grain particles means the valve I use to regulate the sparge flow doesn't tend to clog the way it did when I used the false bottom, which makes sparges go a lot smoother.
(Posted to Web December 8, 1999; Last updated March 10, 2000)