This Mushroom Is the Most Bitter-Tasting Thing Ever Found

You’d be forgiven if you naturally assumed that the most bitter substance on earth was a citrus fruit. But scientists in Germany found what might be the most face-contorting source of bitterness in existence, and it’s not citrus fruit or even a fruit at all. It’s something we more closely associate with the deep, rich, Umami-ness: a mushroom.

Specifically, it’s the Amaropostia stiptica, a.k.a. the bitter bracket fungus. It’s unbelievably bitter, yet non-toxic. It just tastes like it’ll kill you.

The research team from the Leibniz Institutes of Food Systems Biology and Plant Biochemistry found three new compounds in the fungus—oligoporins D, E, and F. These are known as triterpene glycosides, and oligoporin D is outrageously bitter. So bitter that it could elicit a reaction even in incredibly small, highly diluted doses.

You probably know that a single gram of liquid isn’t much. It’s like a fifth of a teaspoon. If you were to drop 63 millionths of one gram of oligoporin D into a liter of water, it would still trigger the bitterness receptors on your tongue. That’s how potent it is.

Bitterness usually warns us that something might be toxic, but nature is weird. Case in point: the bitter bracket isn’t harmful, while famously toxic mushrooms like the deathcap are actually rather tasty. Nature is sending mixed signals.

As I wrote last month, bitterness receptors aren’t just in your mouth. They’re all over your skin, including your lungs and even in your butt. We’re not 100 percent sure why, but the safe bet is the same reason they’re on our tongues: to protect us from toxins. Unlocking the secrets of these unpleasant but safe flavors might lead to breakthroughs in food science, digestion, and maybe finally answering why you like the food you like, yet someone else might hate them.