Tomatillos look quite similar to green tomatoes, and in fact, they're both members of the nightshade family. Tomatillos, however, have a husk on the outside, and I love the ritual of removing each pretty bright-green fruit from its delicate papery wrapper.
But once the tomatillos are out of their husks, the not-so-fun next step is rinsing the sticky residue off. What is this sticky stuff, and more importantly, why is it there?
Turns out that this sticky substance is a natural deterrent against insects. If any insects get through the papery husk, the tomatillo's first line of defense, they encounter the sticky film. This film contains chemical compounds called withanolides that insects find bad tasting. So voila, they leave the tomatillos alone!
Luckily for us tomatillo eaters, the sticky film rinses off quite easily. Now that I know why it's there, I'm not as annoyed with the rinsing process anymore since the film helps protect the tomatillos and keeps them bug-free!