Originally Posted by Nargan
I had been looking forward to this one for months. I finally got the equipment to switch from extract to all grain so this weekend was finally time to do it. Unfortunately, it was a disaster and didn't turn out as intended. In the end, I discovered that my cheapo budget thermometer appears to be horribly inaccurate by about 15 degrees so my mash was almost certainly NOT 152F and was probably closer to 136-140F. Pre-boil gravity was a measly 1.030. Post-boil was 1.048 but only after I did an extended boil because I decided the batch was already lost so why not try to get a usable gravity out of it. It smells ridiculously good right now but it most certainly is not a Zombie Dust clone. I've ordered two new thermometers and intend to call do-over on this recipe in another week or two. I hadn't noticed this problem before because I was brewing using extract and really didn't use the thermometer much.
Sorry to hear. I've never met a thermometer I've trusted. Well, until I bought a thermapen. I occasionally use that for double checking temps. The long stem bimetallic seem the most inaccurate, and forget about that floating thermometer. Also beware of the so called laboratory thermometers, which can get a portion of the red fluid separated from the rest of the column.