Red Section Separator

Spicy exchange / 2022

Why are onions spicy?

Cream Section Separator

Do onions have capsaicin?

Capsaicin is what makes peppers spicy — but there's no capsaicin in onions and they have an SHU rating of 0... so why are they spicy?

Red Section Separator

A bite of raw onion will instantly have your tongue burning and your eyes watering. Instead of capsaicin, it's the sulfurous compounds found in onions that make them spicy.

What makes onions spicy...

Cream Section Separator

The specifics...

Specifically, raw onions contain propyl propanethiosulfonate, propenyl propanethiosulfonate thiopropanal S-oxide, and propyl methanethiosulfonatem which contribute to the flavor profile and spiciness.

Red Section Separator

When you cut into an onion, a chemical reaction occurs, and propanthial S-oxide is generated, which is what makes your eyes burn or water.

Why do onions make your eyes water?

Cream Section Separator

Why are some onions spicier than others?

The sulfur content of the soil and the duration of growing can make onions spicier or less spicy. Spring onions tend to be sweeter, and autumn storage onions tend to be spicier. 

Red Section Separator

Instead of using the Scoville scale, which measures capsaicin, onions can be measured on the Pyruvate, scale which runs from 1-10.

How onion spiciness is measured

Get the free spicy food market report

Sign up for our newsletter and learn the truth about the spicy food market in 2022 and beyond!

Cream Section Separator