Spice levels: Go easy on the kanzuri at first when making this spicy shrimp and mushroom pasta. | MAKIKO ITOH

Yuzu koshō, a citrusy, spicy paste made with chili peppers and the yuzu citrus fruit that is a speciality of Kyushu in southern Japan, has become quite trendy overseas in the past few years. But there’s another deserving spicy chili pepper and yuzu mixture that is not as well known: kanzuri.

Unlike yuzu koshō, which is made in the summer months when green, unripe yuzu and green chili peppers are both available, and is ready to eat in about a week, kanzuri takes three years to fully mature.

The kanzuri product has been a registered trademark of Kanzuri Co. in Myoko, Niigata Prefecture, since 1966, although it is so familiar to consumers, especially in Niigata itself, that it has become a rather generic term for red chili pepper paste from the region. According to the company, the condiment may originate from a hot chili pepper paste consumed by the armies of the legendary 16th-century warlord Uesugi Kenshin.

It’s not the only chili pepper product from the region, however. Just to make things confusing, there’s also tōgarashi miso, which means “chili pepper miso” but has no fermented soybean in it at all. This is a legacy of the days when all kinds of fermented pastes were called miso. It’s also worth noting that tōgarashi and koshō are both names for chili peppers; the latter means peppercorn in standard Japanese, but means chili pepper in some Kyushu dialects.

Sun and snow: In a process called yuki-sarashi, chili peppers are spread out on the snow in Niigata Prefecture to freeze-dry. | PIXTA

What makes kanzuri unique is that it is fermented for a long time with kome kōji (rice inoculated with Aspergillus oryzae, Japan’s “national mold”). Niigata Prefecture, which is on the coast of the Sea of Japan in northwestern Honshu, experiences heavy snowfall in the winter, and is also the top rice-growing region in the nation. Although chili peppers were only introduced to Japan in the 16th century, the three-year process by which kanzuri is made reflects preservation methods that have existed for centuries.

In the fall of the first year, the ripe, fiery red chili peppers are washed and pickled in salt. The following January, the chili peppers are desalinated and spread out on the snow, where they are allowed to freeze-dry. This process, called yuki-sarashi (“exposing to snow”), takes the edge off the chili peppers’ heat, while concentrating their sweetness and umami.

The peppers are then mixed with kome kōji, salt, and both the zest and juice of ripe, yellow yuzu fruit. This is left to ferment and mature in large barrels. In the second year, the mixture is stirred during the hottest days of August to encourage fermentation; this is repeated in the third year. Finally, in November and December of the third year, when the first snow falls, the contents of the barrels are again spread out on the snow to be exposed to the cold air and dry out a little, before being ground into a paste.

This long fermentation and maturation process gives kanzuri a complex, slightly alcoholic character; it has a deep, rich umami flavor along with saltiness, heat from the chili peppers and the muted citrus notes of the yuzu. Although standard kanzuri is aged for three years, there’s also six-year kanzuri, as well as several kanzuri products such as fermented squid, sauces, rice crackers and even kanzuri candy.

Turn up the heat: Mix kanzuri chili paste into mayonnaise for a spicy dip or with a bit of warm, garlicky olive oil. | MAKIKO ITOH

Kanzuri can be used whenever you might use yuzu koshō or mustard paste in Japanese dishes, such as in nabe (hot pot), oden (simmered vegetables and protein), nimono dishes, soups, or on grilled meat, chicken or seafood. It also works well in Western-style dishes — try using it instead of harissa. I like to mix a little into cream cheese or mayonnaise to use as a dip, or into warm olive oil with a little grated garlic. It also adds heat and umami notes to salad dressings and ponzu sauce.

This week’s recipe is for a spicy shrimp and mushroom pasta with a Japanese twist. Go easy on the kanzuri at first, and add more if you want additional heat.

Recipe: How to make spicy shrimp and mushroom pasta with kanzuri

Serves 2

Prep: 15 mins.; cook: 15 mins.

200 grams linguine or other pasta

Salt for the pasta water

16 medium shrimp, peeled and deveined, heads and tails removed

100 grams shiitake or shimeji mushrooms, sliced or separated into clumps

1 tablespoon olive oil

1 tablespoon sake

1 teaspoon grated garlic

¼ medium onion, finely minced

200 grams canned whole tomatoes (½ can)

2 teaspoons soy sauce

1 tablespoon (or to taste) kanzuri

Salt and black pepper to taste

Shredded nori seaweed and green shiso leaves

1. Sprinkle the shrimp with the sake and set aside.

2. Bring 2 liters of water to a boil and add 1 teaspoon salt. Cook the pasta one minute less than the package directions indicate.

3. While the pasta is cooking, make the sauce. Heat the olive oil in a large frying pan over medium heat and add the mushrooms. Saute until lightly browned. Add the garlic and onion, and saute until the onion is wilted. Add the shrimp and saute until just cooked, and remove from the pan to prevent it from overcooking.

4. Add the canned tomatoes to the pan, crushing them with a spatula. Put the shrimp back in, and add the soy sauce. Add the kanzuri and a little of the pasta water, and stir until the kanzuri is dissolved.

5. Drain the pasta, add to the frying pan and mix well with the sauce. Taste and add black pepper and salt if needed. Serve topped with shredded nori seaweed and green shiso leaves.

By Makiko Itoh, The Japan Times

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