Direct Fire Mash - Confusion

Yesterday I noticed a large variance (6-8deg F) between the temp probe at the exit point of the MT vs. the dial thermometer in the center point of the mash.

The MT is 26 gallons. I had 35lbs or grain @ 1.5 qt/gallon ratio.

The dial thermometer indicated 151F (dead nuts for what I was looking for) but the Love controller was reading 158-159F from the probe at the outlet.

The flow rate was already high (march pump) so I'm not sure whats going on.

For most of the mash, the pilot light was providing the main heat source as the love controller was set @ 152F...thus the gas valve was typically closed.

Q./ Anyone else notice large variances between the mash body temp and the recirc outlet point on a direct fire system?

....oh, and my efficiency was crap! 58% Mash time was 90 minutes.

Thanks!

-Shark

This could be a number of different things, but your first step is to make sure that you two thermometers are giving you equivalent readings under normal circumstances. Are your probes calibrated?

After that, you want to make sure you are getting a proper recirculation, as opposed to a single channel pulling liquid from one point to another along the side. What happens to the temps if you stir the mash periodically?

Thanks for the reply. The thermo in the tank is calibrated. I'm thinking of cranking the flow up and increasing the recirc arm holes.

I use a sparge arm at actually makes the top of the grain bed move arond..at the top a lot.

Also, My thought is the mash out temp was too low. Need to crank he temps up a bit and checkk the crush characteristics. Efficiency is one thing but the outflow temp is weird. I don't doubt he termal couple. It may be picking up residual heat from the burners....?

I may have to text Lonnie Mac to solve this one.

MalFet said:

After that, you want to make sure you are getting a proper recirculation, as opposed to a single channel pulling liquid from one point to another along the side.

Click to expand...

This would explain both the temp difference and poor eff.