I built my mash tun using a 56qt standard cooler. I made a bulkhead fitting, added a ball lock and I am using a home made single SS bazooka screen.
I am only hitting about 60-62 percent right now and would much like to improve this. I have tried mashing at different temps “148-158” and it all comes out to be about the same. I get a slightly better efficiency with the higher temps, just a point or two.
The screen runs right down the middle of the mash tun. I was wondering would it increase my efficiency if I were to build a manifold with say two or three screens equally spaced. From what I have read this might help, any suggestions as to how much of an improvement might be seen?
There are a couple things you can do to increase your mash efficiency. However, keep in mind that efficiency is not the end-all and be-all of homebrewing. If your beer tastes good, a 60-62 percent efficiency only means you need to add a bit more base malt in your recipes.
Here are some things you can do to boost your efficiency, though:
1.) Examine your crush — This is the big one. Visit a local brewery and find out what a good crush looks like. Grains should be cracked open and split into a few pieces, not cracked but whole nor ground into dust.
2.) Runoff and sparge slowly and evenly — for most 5-gallon batches, wort collection should take about an hour, preferably 90 minutes if you have the time. Keep the outflow of wort as even as possible.
3.) Keep the grain bed temperature high (around 170 °F) during runoff and sparging. If your lauter tun loses heat during wort collection, this may mean heating your sparge water above 170 °F.
4.) Hit the correct mash thickness — make sure you have 1-1.5 quarts of water per pound of grain during the starch conversion rest.
5.) Check your pH — your pH should be 5.2-5.6, optinally 5.2-5.4 during the mash. If you have unusually soft or hard water, this might be a factor.
6.) Stir the mash a few times during your starch conversion rest — many commercial mashes are stirred continually. This helps a little, but not that much really.
7.) If your lauter tun geometry is such that there are “dead spots,” spots where wort sugars are largely left behind, not rinsed by the sparge water, consider bath sparging. (A batch-sparge brewed beer can tell you if your lauter tun is the problem.)