They do make $100+ thermometers that many swear by, I however, don't have the cash. What I do to combat the problem is use 2 long stem thermometers and two floating candy thermometers. Yup that's right, 4 thermometers. All of them tend to be within 4-8 degrees of eachother. I then take an average of all of them. Definitely not the smartest idea, but I get damn near 86% on every brew.