[Intro plays]

Hank: This little pink tablet is made of a small red fruit called the miracle fruit, a shrubby plant native to West Africa. The fruit itself doesn’t taste like much -- it’s got low sugar content and a slight tang kind, of like a mildly sweet cranberry -- but people don’t eat it for its taste. They eat it because of how it makes other things taste.

Miracle fruit contains a unique protein called miraculin that does something really weird to your taste buds when you eat it: it makes sour stuff taste super sweet. I’m talking like, turning vinegar into syrup and Tabasco sauce into like a super sweet spicy barbecue sauce. [Hank coughs. "still spicy!"]

Since miracle fruit isn’t always easy to find, has a very short shelf life, and miraculin breaks down when it’s heated, people tend pass the fun along by freeze-drying the pulp and mashing it into powder or pills like the one I have right here... Fun times!

So what the heck just happened to my tongue right now? For starters, your tongue is covered in lingual papillae, otherwise known as taste buds. They’re receptors that translate food chemicals into electrical signals that tell the brain what it’s tasting. Each taste bud contains a bunch of taste cells with proteins that bind to the molecules in food, which is how we detect specific flavors like sweet, salty, sour, and bitter.

That is, unless you’re eating miracle fruit. Because when you chomp a berry or suck a tablet, that miraculin binds to specific parts of your sweetness receptors.. Under totally neutral conditions, miraculin actually blocks these receptors, preventing them from picking up sweet flavors in food, which is one reason the fruit itself doesn’t taste like much. But under acidic conditions it does the opposite -- it jacks up your sweet receptors, making them extra /extra/ sensitive. So if you, say, take a bite of lemon or chug some pickle juice, those acids actually cause the miraculin to change its molecular shape, increasing the intensity of its binding power, and changing the shape of those sweet receptors -- making them go haywire. Suddenly all your brain is hearing from your tongue is, that is SWEEEET!

Just how sweet, you ask? Well, artificial sweeteners bind to your taste receptors more aggressively than natural sugars, which is why most of the powder in the little packets isn’t actually the sweet stuff. And one study showed that acid-activated miraculin binds about a million times more strongly than aspartame -- an artificial sweetener -- and nearly 100 million times more intensely than sugar. And if a stronger bond means a sweeter taste, you can see how miraculin would make orange juice taste like maple syrup.

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