What the hell happened?

[Schnitzengiggle]

I have been AG brewing for a while now. I usually double batch sparge, but on occasion have conducted a step infusion mash with high protein grain bills.

However, my last brew day (this past Wednesday) I brewed 10 gallons of a session IPA. My grain bill consisted primarily of 2-row and Maris Otter, a small portion of Crystal 40L, and some Carapils. Yet, I ran into a stuck runoff?

I have never had a problem like this with such a grain bill (lacking rye, wheat, oats, or any other gummy substance). However, there seemed to be a decent amount of protein on the top of my grain bed after getting my MLT to drain.

If it makes any difference, I use a pump, and recirc for lauter, but have never had an issue like this before, especially with such a moderate grainbill.

Any ideas?

 

[ashplub]

Crush too fine perhaps?

 

[Schnitzengiggle]

Crush too fine perhaps?

Good idea, but same crush I have been using for the past couple years. I wish I knew. I was thinking perhaps temperature, it has been much colder here than usual, but the temp in the MLT should be similar, so IDK?

 

[Jbt]

Maybe bottom of the sack fines. I had a real slow run off my last batch also. Again same crush, but there seem to be a lot of fines at the bottom of my 2 row sack that may have got in.