Im getting ready for my first all grain brew, looking to make or buy a cooler mash tun. I can't seem to figure out how the stainless steel false bottom works. In the how-to videos they don't include it, is it necessary?
You don't have to have a false bottom. Another option is a "toilet braid." Like in this one... http://brewing.lustreking.com/gear/mashtun.html
You need to decide if you want a false bottom, or if you want to use a braided tube. Some folks like their toilet braid even. I use a bazooka tube. It's got a copper pipe inside of the tube to make it rigid and helps to make sure it doesn't get all beat up when I stir the mash. It's got slits cut in the tubing to help aid in draining the mash tun. You can install your ball valve, put the coupling on the inside, and screw in the bazooka tube to help filter. Takes me maybe 1 1/2 to 2 quarts during the vorlauf to get a really clear running.
I use a false bottom, and have never used a bazooka tube for the mash. One or the other is necessary, but I couldn't tell you which is better. I can tell you that the tube is cheaper.
I use a copper manifold in the bottom of my cooler. It's a 48-qt rectangular. Most of the false bottoms I see are made for the round coolers, mostly the 10-gallon Igloo type as seen on construction sites everywhere.
I use 5 gallon rounded cooler and simple "Stainless Steel Washing Machine Connector" simple assembly, affordable and works fine. The other stuff on how to build it checkout youtube.
Doesn't the choice btwn false bottom and toilet / bazooka braid depend on how you sparge? Don't braids tend to channel flow from a fly sparge?
I bought a bulkhead fitting and a ball lock and attached it to a copper manifold that I made for mine rectangular cooler. I used a Dremmel tool with cutting disk to make slits on the copper pipe at approximately 1 cm intervals.
It doesn't have to, but it should. If you have a round cylindrical cooler, you'll do better with fly sparging, and should have a false bottom for that. A braid typically works well for rectangular coolers, and probably channels, but you're batch sparging. Batch sparging tends to even out between stirs anyway. Could you bazooka from the bottom of a cylindrical cooler well? Sure. Could you fly sparge out of a rectangular mash? I've seen a lot of pictures of small breweries do it.
I use a bazooka screen at the bottom of my 7 gallon stainless-steel-pot mash/lauter tun. I regularly achieve >88% mash efficiency with fly sparging, so channeling is not an issue for me. Several things probably help with the efficiency: (1) My mashes are usually fairly thin (2 qt/gallon on last batch). (2) At the end of the mash I add some sparge water to the mash to thin things out even more and then heat it all to 165 F. (3) I then fly sparge for 50 minutes to 60 minutes (depends on amount of sparge water), keeping the liquid level in the tun constant until I'm out of sparge water.
