The Spicy Spectrum

Go ahead and take a bite from that bowl of raw onions you’ve got sitting next to you. Hey, no judgment here!

How would you describe that taste? Could it be fair to describe onions as spicy?

Let’s talk about what makes something hot or not. Today, let’s talk all about the spicy spectrum.

Imagine a hot dog with a bunch of ingredients on it. They’re all different types of spicy, but they’re also kind of clumped together, so all the onions are down there at one end. Over on the other side of the hot dog are jalapeños, which most folks would describe as spicy without hesitation.

This heat is produced by capsaicin, which activates the same nerve receptors as actual heat. In other words, jalapeños and other foods with capsaicin in them make it feel like your tongue is being burned by heat.

Capsaicin isn’t the only chemical in foods that feels this way. Take black pepper, for instance—the spiciest thing on my dinner table growing up. The compound called piperine is responsible for the mild burning sensation you feel on your tongue or in your nose when you put some black pepper into your soup.

Then, there’s wasabi, or mustard, or horseradish. All three of these burn your nose a lot more than they burn your mouth, right?

The chemical compound behind this feeling is called allyl isothiocyanate, and it activates a different set of receptors. The burning sensation ends up in your nose instead.

Now, let’s turn back to that half-eaten bowl of onions. You’ve been busy!

note: don’t feed actual goats onions. therianthropes are fine

When you bite into a pepper, you get the spicy sensation right away. That’s because the capsaicin is already out there, ready to eat—but onions are different. The cells themselves contain a little chemical defense system. This means that hungry herbivores get an unpleasant experience when they bite into an onion.

This effect is true for peppers too, but the onion has that little delay.

We have sulfur to thank for this. We can also thank the sulfur compounds that disperse and transform as you apply heat, so a cooked onion is nowhere near as pungent as a raw one.

So, is that spoonful of onions you’re chewing on spicy, or merely delicious?