Channeling in mash


i brewed my first batch with Robobrew ( Cream of 3 Crops recipe) and had issues with a VERY slow Sparge. It took 3 hours.
A t cleanup of the malt pipe, I noticed that the grain bed was very compressed ( much denser than in my previous cooler mash tun) and that it did not extend all the way to the side of the malt pipe. The filter bed was somewhat cone shaped with the lowest part of the grain bed about 1/4 inch from the sides of the malt pipe, and the top of the filter bed was a good 1/2 inch from the sides of the malt pipe. I was circulating during the mash,
Is this channeling normal? Was I circulating too fast?


I too have had compacted mash and very slow draining even with rice hulls . I did not notice if i had the cone shaping of the grain bed because i broke out the mash paddle and tried to break up the compressed grain. I did not vorlauf and performing one is never mentioned anywhere. I bet this will help and will be doing so next time. Also i think lifting the grain tube slowly will help. By pulling up the tube with all that grain suspended in the wort the draining action of the liquid would pull down the grain as it quickly flows out. Lifting it out slowly say on a rope and pully i think will help a lot too. Just a few thoughts and observations.


Hi Guys, I’ve just joined the forum so am catching up with posts.

When I’m ready to sparge I raise the grain pipe, using a pulley attached to the roof of the shed, and rest it on the points inside the main body of the unit. Once most of the wort has drained out I put my sparge water into a watering can and spray it evenly over the top of the grain bed.

Cheers, Doug


I think I solved my issue. When the issue occurred , I had the wort recirculating tube positioned so that the wort was traveling in a circular direction around the outside of the kettle. . Since then I have the wort recirculating tube postponed so it does cause this circular motion. No more channeling along the edges of the grain tube.


My first Robobrew had a 3hr sparge … It’s a common problem in these tall mash tuns. I even tossed in a few handfuls of rice hulls.
The BEST solution is to grain condition before you grind your grain. spray water ( 2% of your grain bill weight … so 10lbs of grains is 160oz, 160oz * 2% = 3.2oz of water) evenly on your grains, let sit for 30min or so, then mill. The grain hulls will hardly break apart at all and the kernel will crush perfectly. These hulls act as a separator in the mash allowing the wort to evenly flow through it.
I’ve NEVER HAD A PROBLEM since I’ve started doing it, it’s awesome!!!



Hi All, I’m new to the forum. I’ve owned my Brewzilla 3.1 since January this year, and read with interest the many posts about the problems people have had. I’ve experienced a few of these problems already myself, but have managed to work around things by using a bit of old fashioned British ingenuity. However, I have recently bought a grain mill, and I’m curious about the benefits of moisure conditioning the grain before milling, and the claim that it helps the flow through the mash (I currently use a LOT of rice hulls). I understand the principle of spraying the grains, but can someone please tell me how you get an even distribution of moisture throughout 5kg of malt grains? This is a lot of grain to spread out on the kitchen worktop . . . . . and the resulting mess would not go down well with my wife :unamused: