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HERMS re-circulation temp.

beerdog

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HERMS is something that I have been considering for a while now, but I have a nagging question about the wort temp.  When the wort is circulated through the hot water of an HLT, does the temp of the wort actually reach or approach the temp of the water in the HLT?  I would think you would want to limit the circulating wort temp to below 160F, so as not to increase dextrins.  Is the temp of the wort leaving the HLT monitored to prevent over heating of the circulating wort, or is this not a concern?  :-\
 
The temperature for travelling wort isn't the same as the temperature of the source. There is as much as 15 degrees Fahrenheit and as little as 4 degrees difference, depending on the velocity of the wort. Typically, you're going to be somewhere in the middle (about 6 to 8 in my experience).

Enzyme activity isn't completely destroyed by temperature until you're between 175 to 180F, it's simply temporarily stopped and accumulates about 25% denaturing per 5 minutes held at above 165F. With a reasonable flow rate, both HERMS and RIMS systems have heat contact for less than a minute.

 
Thanks.  Judging by how popular those systems are, I was sure there must be a simple answer.  So the temperature rise of the wort is minimized due to flow rate and or length of the tubing run inside the HLT?
 
beerdog said:
So the temperature rise of the wort is minimized due to flow rate and or length of the tubing run inside the HLT?

Typically, yes. Longer coils immersed in the HLT will have shorter rise times and pull heat faster from the HLT. It's just a repurposed wort chiller.
 
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