With its root in Kyushu's food traditions, yuzu koshō is a salty, citrusy, spicy condiment.
Although it was originally made in local homes, within the past few decades, companies have begun bottling and selling yuzu koshō commercially, leading to an increase in its popularity. Due to the sustained national boom these past 10 years, this local Kyushu condiment is now made all over Japan, to varying degrees of success. And, thanks to a few key producers, such as Kushino Nouen, who make yuzu koshō responsibly and ethically, using local materials without additives or preservatives, Japan's yuzu koshō boom shows no signs of letting up.
More recently, yuzu koshō is becoming well-known beyond Japan, perhaps because of the worldwide craze for ramen. And while yuzu koshō is extremely well-suited to salt-broth ramen, I like it thinned with olive oil and used as a drizzle for kelp-wicked sashimi or mixed sparingly into vinegar for a spicy mignonette alternative on oysters; but stirred into mayonnaise and slathered on a thick sandwich or as a dip for oven-baked French fries might be its best use yet.