Because I failed to re-calibrate my thermometer. :oops:
I was at least 7 degrees low, meaning I mashed at roughly 144. I have tasted the end product and it is thin and dry and not at all what I was going for.
I guess the reason for my post is to ask how often you all re-calibrate your thermometers, and to ask if this has ever happened to you. And if so, what was your end result? The beer is really not very good… 
For what its worth. . .
I have a lab thermometer that I checked against my high school’s (I teach not attend) lab thermometers this fall.
I use the lab thermometer to take temps that I can wait on - grain temp to calculate my strike water temp. I check my digital against this at this time.
As my strike water heats I take its temp with both the lab therm and my digital therm. If they read the same (and they have since I replaced my digital) I just use the digital during the rest of the brew.
[quote=“greatplainsbrwr”]For what its worth. . .
I have a lab thermometer that I checked against my high school’s (I teach not attend) lab thermometers this fall.
I use the lab thermometer to take temps that I can wait on - grain temp to calculate my strike water temp. I check my digital against this at this time.
As my strike water heats I take its temp with both the lab therm and my digital therm. If they read the same (and they have since I replaced my digital) I just use the digital during the rest of the brew.[/quote]
Interesting. Do you implement this procedure to save wear and tear on your lab thermometer, as in dropping, getting it wet etc?
I use a Big Boy Thermomiter and check it before evry brew day in 32F water. I find that half the time it’s fine the other half I need to adjust it by 2 deg F
The digital is just faster. I just like to check it against the lab thermometer.
