HERMS with low efficiency

[Anguslow]

I have a HERMS that is giving me very poor efficiency, anywhere between 52-63%. I have tried a few things, but nothing is working.

1. Checked my grain milling and I have a good crush with a good mix of flour and cracked grains. There has not been a single stuck or slow sparge.

2. I checked the temperature of the mash using multiple methods (one meter was professionally calibrated) and it was too high. Found the HLT with the electric heater was stratifying and the heat exchange coil was in the upper portion. Added a fan with a water agitator to get the water moving so it is now a constant temp. The mash was spot on where I needed it to be.

3. Considered the temp controller was measuring only a small area of the mash, so instead set the HLT to my target temp and have the pump circulating the wort constantly. Checked various areas of the mash and they were all at target temp.

4. Heated the HLT up to 168 with the pump running to heat the mash and had good flow into the kettle. Took about 10 minutes to sparge.

My only thought at this point is to add a mash stirrer to the system to prevent dough balls and to ensure no channeling. Any other ideas?

 

[Bensiff]

10 minutes sparge...that is pretty much a batch sparge and lower efficiencies would be expected. Try doing an actual fly sparge next time, giving it 45-60 minutes so that you are down to around 1.010-1.014 when you stop the sparge and see what happens.

 

[Anguslow]

Good input and something I had not considered. Would this be an issue even after running the wort through the hlt until the mash reached 168? I would have thought the heating of the pumped wort would have helped dissolve the sugars, which is why channeling was an option. Still, I will try the longer sparge on the next batch.

Thanks.

 

[k_mcarthur]

Yes, longer sparge will help a ton! I stop my pump, and rearrange hoses so I am pumping hot water from hlt through heat exchanger and then into mash. I connect a hose from mlt to my boil kettle and shut all the valves closed. Turn pump back on and just crack valve on pump slowly adding water to top of mash until there is about an inch of clear water on top of the heavier wort. Then I crack the valve on the mlt to start slowly draining into boil kettle. Make sure the input matches the output and wait. The science behind the difference in gravities between the heavier wort and the lighter water helps to rinse more of the sugars off the grains.

 

[Yooper]

Good input and something I had not considered. Would this be an issue even after running the wort through the hlt until the mash reached 168? I would have thought the heating of the pumped wort would have helped dissolve the sugars, which is why channeling was an option. Still, I will try the longer sparge on the next batch.

Thanks.

It's true that a mash out may make the sugars slightly more soluble, but it won't affect the efficiency, or the sparge.

I'd suggest either batch sparging or a proper fly sparge. Either would be fine.

Fly sparging works on the principle of diffusion- the slow drain without channeling is absolutely critical in this.

Batch sparge relies on stirring well, to knock the sugars off of the grain so to speak, and then drains fast.

Either way works very well, when done properly.