Thermometer Check: Calibrating

posted in: Equipment | 0

I am using this thermometer I bought off Amazon back in September for checking my home brew temperatures.  I like that I can stick it on the fridge and use it whenever I need it for brewing or cooking.

Im not sure when or why I decided to do this, but I could not stop asking myself, “Is my thermometer even close to what it is reading??”  A quick search led me to this video.  In the video they show two different ways to check or calibrate your thermometer.  It looked very easy so here is my version and how I checked my thermometer:

First I grabbed a small glass and filled it with crushed ice and enough bottled water to just cover the ice.  Then I popped the thermowand into the glass, being careful not to touch the bottom or the sides of the glass:

freeze31.7F, not bad considering they are claiming an accuracy of +/- 0.9F.  So I’ll note that and remember that for the cold side.  I was looking for 32F with this test.

For the boiling water check things for a little more complicated but it wasn’t difficult at all to find what I needed.  While the bottled water was boiling I just online.  The two things I needed to know were my current elevation and at what temperature water boils at that elevation.  It took a few different searches to find them, but we got it.  For the elevation I found  Who would have thought that was a URL?  I just have them permission to use my current location and they told me I was at 1039ft.  I went back to google to find out at what temperature water boils at my current elevation.  This online calculator seemed pretty legit so I plugged in my elevation:

Screen Shot 2015-01-25 at 9.54.57 AMSo my water boiling point is 210.16F at an elevation of 1039ft.  My water was boiling, I had my target temperature, so lets see what I got.  Again, being careful not to touch the bottom or the sides of the pot:


Not so good.  I am about 1 degree off, but at least now I know that I’m going to want my temps about a degree over my target.  I’m not super anal about my home brew temps being EXACT so this wont kill me, but I will definitely want to have everything just a bit higher from now on.  If you can adjust your thermometer to get almost perfect, I’m jealous…


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