mash recirculation cause stuck/slow sparge

[jedheuer]

hey all,


I do a mash out recirculation at the end of my mash and most the time it causes a slow or stuck sparge. What could be the cause of this? Is it likely that my crush is too fine? (I think my efficiency is around 70%). or do I need some rice hulls? Anybody out there have any problems recirculating their mash? I am using a cooler with a false bottom as a mash tun. The false bottom is the round steel type with small holes in it.

thanks!

 

[Osedax]

Rice hulls will help most of the time. You should start slow to set the grain bed and then you can ramp it up a bit. Too fast too soon will compact the grain bed leading to a stuck sparge.

Also, check your crush against the photos on here. Make sure it isn't too fine. Do you batch or fly sparge?

 

[BrokenDog]

You are likely just draining too fast and compacting the grain bed. Slow it down and try to keep the liquid coming out equal to what is going in.

 

[jedheuer]

ah, I see i am starting it up full speed. I will try a slower recirc.

Thanks!

 

[turkeygecko]

Why are you recirculating only for mashout? If you recirculate during mashout, not sure why you wouldn't recirculate during entire mash process.

 

[turkeygecko]

You are likely just draining too fast and compacting the grain bed. Slow it down and try to keep the liquid coming out equal to what is going in.

Not following this either. Recirculating requires the volume coming in is the same as the volume going out...

I had some stuck mashes with my HERMS. For me, it came down to widening my mill gap to 43 and getting a better designed false bottom/MLT (Blichmann Boilermaker). I avoided coughing up the cash for the Blichmann as long as possible, but it fixed my stuck mash problems. Start with widening your mill gap, mash with a thinner ratio, add rice hulls, and lauter a few quarts to set the grain bed before recirculating via pump with valves wide open. Start recirculating slowly, and increase rate after a couple minutes. Good luck!