A friend offered me the loan of his infra-red thermometer (a sort of a handheld unit you point and shoot), so I was dead pleased as its a proper scientifically calibrated unit.
So put in me giant tea bag of grain, and just for the craic then use my crappy Chinese-made probe, and its out by a full 10C, so far so you'd expect. Then half an hour through the mash I use them both again, and this is where I start to get worried, the IR thermometer reads 55C and the probe 70.1C, but I touch the pot and it doesn't feel like 55C at all it feels way hotter. Panicking a bit and I taste it, its not sweet at all, so its not converting at all, its like a pot pot of auld tea :'(
Is there anything on earth I can do assuming I've killed off the enzymes?
Is there any point putting in a kg or two of pale malt assuming it can convert 3 times its own weight?
Any point in adding more pale malt at this point?
IR thermometers also have issues with steam
The reading from an IR thermometer varies according to the colour of the surface being measured. If you want to get an exact reading, to 'calibrate' it you need to take a reading from a surface of a known temperature and change the 'e' (emissivity, varies from 0-white to 1 black) reading on the probe until the temperatures match. The cheaper guns don't have this option, they're usually set to a default value of 0.8, so to eliminate variation the best thing to do is put some black insulation tape on the surface of what you're measuring and measure that.
They're handy for when you want a quick measurement of something from a distance, but for a mash where this isn't an issue you'd be better off with a reliable temperature probe instead.
Cheers for the bit on the IR gun, it did have an e value on it. In my ignorance I assumed it'd be better than my e2 probe. Anyway roll on a decent set up at Tog.