What's That Smell??

You've undoubtedly noticed that some vegetables are smellier than others. Corn, carrots, lettuce, green beans - they don't have much odor to them. But what about onions, garlic, and cabbage? Whew! These vegetables can make your eyes water, especially when they're cooking. Why does that happen?

All of these vegetables contain the element sulfur. In its pure form, sulfur is a light yellow powder that doesn't have much of an odor. But if you combine it with some carbon, hydrogen, and maybe a little oxygen and/or nitrogen, you can make some of the stinkiest molecules on earth! These molecules evaporate into the air easily, which is why you can smell them. The good part is that, when you cook these vegetables, the smelly sulfur-containing molecules leave. That means that they're pretty stinky while they're cooking, but that they taste much different (and often better) when they're done.

Try cooking some cabbage to check this out. Take a head of raw cabbage and cut it in half (have an adult help). Smell and taste both halves - they should be the same. Now cut one half into small pieces and place the leaves into a saucepan with 1 cup of water. Boil uncovered for 20 minutes. How does the cooking cabbage make the room smell? When the cabbage is done, remove a piece and let it cool. Compare its taste and smell to that of the uncooked half. What do you notice?

The kitchen got pretty smelly while the cabbage was cooking. That's because the sulfur-containing molecules left the leaves and went into the air. But the cooked cabbage tasted and smelled quite different from the uncooked cabbage because all or most of the stinky molecules had evaporated!