What is this stuff?

April 13, 2008 8:46 PM

What are the little black pebbly things that are in the bottom of this floating thermometer . Are they what makes it float? Are they toxic?
posted by danb1 to Science & Nature (6 answers total)

Probably lead shot, it acts as ballast to keep the thermometer upright in the fluid.
posted by Floydd at 8:54 PM on April 13, 2008

Perhaps tungsten instead of lead. In a food thermometer I doubt there would be anything toxic. As Floydd said, its there so the thermometer floats upright.
posted by TheJoven at 8:58 PM on April 13, 2008

Since it's sealed inside glass, it doesn't really matter if it's toxic. I suspect it probably is lead, because tungsten would be more expensive.

If it weren't there, the thermometer would naturally float on its side. The bulb wouldn't be fully immersed. And it wouldn't really read temperature correctly. Also, it would try to read the temperature on the surface, where it's hottest, rather than down a couple of inches, which is more typical of the batch as a whole.
posted by Class Goat at 9:06 PM on April 13, 2008

Best answer: If you are asking because you *broke* the glass, I would say throw the batch out. Leaving an unknown, possibly toxic, material in with your wort for days does not make for good beer.
posted by exphysicist345 at 9:34 PM on April 13, 2008

FWIW, the last time I broke one of these I was surprised to learn it was bismuth (as is most so-called "lead" shot these days). After much dicking around, I managed to melt it and get some tiny little crystals.

Next time I'm at my BIL's farm, I intend to try melting some shot and growing bismuth crystal for my nephews.
posted by Pinback at 2:51 AM on April 14, 2008

Response by poster: I've found some anecdotes of people doing this and am a little concerned. The balls are metallic, so I don't think they are lead. I will at least try the beer to see if it any good or not.
posted by danb1 at 5:53 PM on April 14, 2008