Had my first stuck mash in the Robobrew

[skarz]

So this is my third or fourth brew and I experienced my first stuck mash. Looking at the grain bill below, it seems pretty standard and is well below the max grain capacity of the Robobrew. I used about 4 gallons of water for the mash. I am fairly convinced the stuck mash was due to grain getting inbetween the dual layered bottom screen (see pic below) featured in the Robobrew v3.1.1. In the future, would it be OK to skip the finer mesh bottom in the malt pipe to avoid the grain getting stuck and clogging again? Also are there any other possible reasons for the stuck mash?

MALT/GRAIN BILL

8 lb (3.6 kg) Pale malt (2-row)
9 oz (255 g) Brown malt
9 oz (255 g) Kiln Coffee malt
7.5 oz (213 g) English Dark Crystal malt (77°L)
4.5 oz (128 g) Biscuit malt
4.5 oz (128 g) Chocolate malt
2 lb (907 g) pumpkin

 

[Maxkling]

Did you mash the pumpkin? If so that would be the reason.

Edit, let me clarify as I always mash pumpkin with my pumpkin ale. Extra special care has to be taken with lots of rice hulls, slow flow, and trial and error. I’ve had a stuck mash with pumpkin too, but in a traditional tun with a manifold.

 

[skarz]

Sorry I should have clarified, the pumpkin was only added during the boil.

 

[Maxkling]

Did you crush the grains?

 

[skarz]

Did you crush the grains?

They were crushed by my LHBS.

 

[Jag75]

maybe you compacted it too much ?

 

[Sammy86]

Did you stir the mash at all after dough in?