This 'mash tun with a porous bottom' allows mashing directly in the 3-in-1TM and 4-in-1TM fermenters, saving you space, time and money. Having completed the mash, the colander is lifted from the top of the fermenter, removing all the grain with it while the wort drains out the bottom into the fermenter where it is ready for boiling. The Mash ColanderTM brings all the benefits of a Brew In A Bag (BIAB) style brewing without any of the limitations. The Mash ColanderTM is included as part of the All-in-1 BIACTM system.
The Mash Colander can be chosen with a perforated or wedge wire false bottom (pictures at the right show both types). While with proper crush size and monitoring the flow rate to minimize pressure differential inside the Colander either bottom can work really well, a wedge wire false bottom is more common in commercial breweries because 1. it provides more open area, 2. it supports the grain better as the largest gap width is smaller than with a perforated bottom, and 3. it won't trap grain as easily (if grain gets into the the perforated hole, it is trapped there, but with the inverted triangle shape of the wedge, it can often work itself out and fall down to the bottom where it can be returned by the pump back up to the top of the Colander).