Now, aside from making fake volcano simulations, you can actually get some recording done with this stuff. Science! Photo (CC-BY-ND) Rodrigo Huerta.

Need a new mic to play with? Maybe you should raid your kitchen pantry.

London-based musician Leafcutter John writes us to share a detailed tutorial on cooking up new mics from common household ingredients:

Real Sound Cookery – Make a contact mic with baking soda and cream of tartar. [leafcutterjohn.com]

That in turn is inspired by a terrific, detailed video by our friend Collin Cunningham for MAKE:Magazine (Collin’s also been a regular at our Handmade Music series in NYC).

The result: you’ve got the material to do some field recording or experimental sound design. Leafcutter John shares a bit of hands-on experience working with the thing, and has a sample recording up on SoundCloud:
First recording using Rochelle Salt piezo crystal made from baking soda and cream of tartar by leafcutterjohn

Also, and I don’t say these words very often, here’s a brilliant YouTube comment:

wait… mounting the crystal in place… THIS IS HOW THE BLACK MESA INCIDENT STARTED! :O

(Google it if you don’t get it.)

More great info from Leafcutter John:
Leafcutter’s DIY Steel Can Hydrophone & Preamp. Step-by-step guide
Shit I’m a Geek / The joy of Piezoelectricity [good background on the above]

(Side note: preamp is the really important part of the hydrophone equation, which I managed to screw up recently. Stay tuned for my tale of how to do it right, after I actually do it properly. DIY electronics is no fun, anyway, if you don’t occasionally completely botch it.)