« on: January 06, 2010, 02:09:34 PM »
I've done dozens of partial mash and all grain brews using Denny's cheap'n'easy mash tun design, and it's always worked well for me.
This past week I brewed a Munich Dunkel with 94% Weyermann Munich I malt, 3% Carafa Special, and 3% CaraMunich. I belive my crush was finer than I normally crush, since there was a lot of flour. I did something different with this batch by adding water slowly to the grain in the tun, rather than vice-versa. Ultimately, I mashed at 152. When I went to vorlauf, as soon as the runoff cleared, it slowed to a trickle. I tried to stir up the bed, and the same thing happened. I attemped to move some of the mash to a different (smaller) tun with the same design, and it got stuck there too.
I ended up changing out the hose that passes through the wall of the cooler to one that had a large ID with the same OD... unfortunately, this is a regular, non hi-temp tube, so I prefer to use the original tube I had been using. Nevertheless, it, along with a lot of patience, helped me to get through the brew day.
I noticed that there was a rather thick (.5 - 1.25") layer of trub/mud/protiens that sat atop the grains once my sparge was complete. I have seen a thin layer of this substance before, but never has it been so thick. I assume it was this substance that was causing the stuck sparge.
It is likely that this was caused by my crush? Or is it possible that at some point I unintentionally throughout this pricess did some sort of temperature rest that caused a thick, muddy like protien to form in the mash?
Next batch, I will be using a coarser crush, but I thought I would ask the group here for opinions as well.