Solved! A Stuck Mash Saga

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Jan 28, 2010
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I've brewed about half a dozen batches on my new eHerms system, and the biggest problem I've struggled with is getting a stuck mash during recirculation. The pump would start pulling a vacuum, the MT outlet hose would fill with bubbles, flow would stop, and I'd lose all temperature control. I'm using a 10 gallon Spike mash tun with the factory false bottom and the pump is a Riptide. Grist is 100% barley. For anyone in a similar position, here are the changes that solved the problem for me:
  • Added a 90 degree elbow to the mash tun outlet and shortened the hose so that there are absolutely zero bends in the hose between the MT and the pump.
  • Increased my grain mill gap setting to 1.05mm. Everyone says to start with 1mm but that was too fine for this false bottom.
  • Increased my water:grain ratio to at least 1.6
Somewhat related but less important:
  • After transferring my strike water to the MT, I used to mash in right away. Now I refill the HLT, start circulation, and bring everything back up to temperature. This keeps the HERMS coil fully submerged in the HLT, which gives me much better temp control. FWIW I lose exactly 6 degrees in the MT during mash-in.
  • Swapped my wooden mash paddle for a giant whisk, which does a much better job of getting the grain wet fast.
  • I was having a really hard time getting the pickup tube in and out of the false bottom. I fixed this by replacing a section of it with silicone tubing (pictured below).
I was planning to try rice hulls next, but had no issues on my last mash, so I think I'm all set!

Photo of my ESB included for good measure. Cheers!


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