Lesson learned; callibrate thermometers

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

lou2row

Supporting Member
HBT Supporter
Joined
Jul 12, 2009
Messages
517
Reaction score
49
Location
NW Ohio
Been using a thermometer I got at Wally World for the last year. I bought a couple through Cynmar, but this one hooks to the kettle, so it was easier to use. Most batches were extract kits, and didn't notice many issues that couldn't be explained.

Last couple batches were all grain. Off a little on the OG; bad grind, fine. But I was never getting down to FG. Not even close. Been scared to death of bottle bombs, but not a one. Beers that have been carbed up to drink seemed a little sweeter than expected.

Doing a batch last night. As I was bringing water up to mash temp, I pour the grains in (BIAB). It is taking forever and when I went to check temp, I didn't see where I set the thermometer. I go grab my laser thermometer out of the tool box, and it reads 168 degrees. I put the other thermometer in and it says 145. I want to see which one is off, so I get the lab thermometer out. It shows the laser is closer, but they both are reading low! It went up to @ 175 degrees. I quickly pour a gallon of cool water in, and it drops it to 152. I cover and let it mash.

So I have been mashing @ 20 degrees too high on every batch! I spent the evening cussing myself since I know better than to not check thermometers out for accuracy.

Just thought I would post this to hopefully warn others from getting a cheap thermometer and not making sure it is accurate.
 
It might not matter, but if it's a dial-type thermometer, with a nut where the dial connects to the probe, it's likely adjustable. http://www.foodsafety.wisc.edu/assets/pdf_Files/Calibration_thermo.pdf

No, it is a alcohol filled on a stainless backing that has the numbers. I thought it could have slid, but the thing is in their tight.

I have a dial type that was off a bunch. I adjusted it, but the adjustment was so loose, I feared it would turn on it's own, so quit using it.
 
I have started to cross check my temps with a digital food thermometer. My mash tun has a dial thermometer in the thermowell so I use a digital food, and a quick read dial to measure the grist directly as a cross check...I'm paranoid :)
 
Back
Top