Medically, an ultrasound scan uses high-frequency sound waves to generate state-of-the-art images of the body’s internal organs—or, if you happen to be pregnant, to track the developing fetus and tell you whether to expect a boy or a girl. It turns out it’s also a potentially invaluable tool for monitoring the quality of your chocolate bar.

Chocolate is intimidatingly complex stuff, containing up to 600 different chemical compounds—three times more, chocolatiers like to point out, than red wine. Many of these contribute to chocolate’s richly varied flavor. Other compounds like serotonin, the “happiness hormone,” and phenylethylamine, the “love drug,” are mood-enhancers. That’s why indulging in a bag of chocolate truffles gives us a lift.

However, it’s