Recirculated mash - no added heat

[cyclonebeer]

Anybody ever try to recirculate wort during the mash without adding heat? I mash in a cooler and I think i could insulate my silicone tubing with copper water line insulation and minimize heat loss while recirculating. Kind of like a poor man's RIMS.

 

[Face Eater]

Should be doable but I would think it would have an increased heat loss. I haven't tried it but just my thought process.

 

[cyclonebeer]

I did a very unscientific trial the other day. As a control, i put 5 gal of hot tap water in my mash tun and measured the heat loss over 1 hour. Then, I put 5 gal of hot tap water in the tun and recirculated through insulated silicone tubing and measured the heat loss over 1 hour. I saw an additional 13% loss of heat. Then, I recirculated through non-insulated tubing and saw a 206% increase in heat loss. I'm thinking this might work. Then again, maybe not.

 

[MidTNJasonF]

On my old system I did this but only during the last 10 or so minutes of my mash and during the batch sparge. For 45 minutes or so I just did a traditional dough in, stir up, and let it sit mash. Then I would begin to recirculate for 10 to 15 minutes before running it off the the kettle. I would dump in my batch sparge water and recirculate for an additional 10 to 15 minutes. As a general rule I would get great efficiency, clear wort with no husk/grain particulate in the kettle, and a great rinse of the grain bed. It was simple to do and caused me no real additional work or effort.

 

[haerbob3]

the only time I do this is with a batch sparge. Otherwise ithe wort is running thr the heat excahngering

 

[cyclonebeer]

On my old system I did this but only during the last 10 or so minutes of my mash and during the batch sparge. For 45 minutes or so I just did a traditional dough in, stir up, and let it sit mash. Then I would begin to recirculate for 10 to 15 minutes before running it off the the kettle. I would dump in my batch sparge water and recirculate for an additional 10 to 15 minutes. As a general rule I would get great efficiency, clear wort with no husk/grain particulate in the kettle, and a great rinse of the grain bed. It was simple to do and caused me no real additional work or effort.

Did you insulate the lines between the tun and pump, or was any heat loss in those last 10 min. inconsequential. Do you remember what kind of bump you got in your efficiency?

 

[MidTNJasonF]

No I did not insulate. (1/2" thick wall silicone tubing) I found the heat loss inconsequential especially since I was about to add hot sparge water a few minutes later.

Oh and efficiency went from low 70's to low 80's but I can not isolate it all to the recirculation since a couple other minor things changed as well. If I had to guess it was mostly the recirculation though. I have done this with grain crushed on my own mill, grain crushed on a friends mill, and grain crushed on my LHBS mill. All were within a few percentage points of each other.