Wasabi-zuke (Shizuoka wasabi pickled in sake lees)

What it is

Wasabi-zuke (山葵漬け) is the wasabi pickle of Shizuoka. Fresh wasabi stems and roots are chopped fine, salted overnight, squeezed dry and kneaded into sake lees, the pale, sweet-smelling solids left after sake is pressed. After two or three days in a sealed container the mixture turns pungent and is ready: a green-flecked, sticky paste that is eaten in small amounts.

It is not freshly grated wasabi and it is not the tube paste sold for sushi. The heat comes from chopped wasabi tissue held in lees, and the lees add sweetness and a sake aroma that grated wasabi does not have. MAFF describes it as a dish mainly enjoyed by adults for that combination of sharp heat and rich lees flavour.

Where it comes from

Shizuoka's water-wasabi grows in terraced beds of clear, flowing spring water. MAFF's regional-cuisine entry says wild wasabi from Mount Butsudani (Ariga-Higashiki, Shizuoka City) was planted by a spring in the Keicho era (1596-1615), and that cultivation spread to the Izu area in the mid-18th century. The tatami-ishi ("tatami stone") method of laying stones in the bed, developed in Naka-Izu, then carried the crop across the prefecture. The Japanese page adds that Tokugawa Ieyasu, who spent his later years at Sunpu Castle, reportedly banned taking wasabi out of the Ariga-Higashiki area. These are local accounts rather than a single documented origin.

The pickle itself is later. It is said to have begun when it was sold at Shizuoka Station, which opened in 1889 (Meiji 22), and it is still a popular souvenir as well as an everyday household side dish. MAFF names three parts of the prefecture: the Shizuoka City area, the Izu Peninsula, and the Gotemba and Oyama area in the east.

Shizuoka is not the only wasabi landscape. Azumino in Nagano grew its industry in spring-fed channels cut into land that had been pear orchards, between the Meiji period and the mid-Taisho period. The Shizuoka pickle belongs to the first of these traditions; the Azumino accounts describe cultivation, not this recipe.

Why the method works as it does

Wasabi's heat is not present in the intact plant. It is made when the tissue is cut or crushed, so chopping into pieces of about 3 mm is what gives the pickle its pungency. The page says the pungency develops over the two to three days in the sealed container, which is why the finished pickle is described as ready when it becomes pungent rather than when a fixed time has passed.

The overnight salting and the squeeze serve texture and flavour: salt draws water out of the chopped tissue and the cloth wring removes it, so the wasabi can be worked into the lees without thinning them. Sugar and a pinch of salt are kneaded into the lees first, and sake is added a little at a time to loosen them to a workable paste.

If the finished pickle is too fierce, MAFF suggests leaving the lid slightly open so some of the heat escapes. That is a flavour adjustment, not a safety step.

Two readings of the salting step

The English MAFF page says to blanch the chopped wasabi with 2% salt, while the Japanese page says to rub it with 2% salt and leave it overnight. The Japanese wording does not mention blanching, and the overnight rest of at least six hours is in both. Neither page says what the 2% is a percentage of, so a salt weight cannot be worked out from the 450 g of wasabi. The method above follows the shared steps and records the difference rather than choosing one.

Eating it

Wasabi-zuke is eaten all year, spooned onto hot rice or served as a snack, and the Japanese page pairs it with sake. A little goes a long way. It is sold widely in Shizuoka supermarkets, food shops and station souvenir stalls, and MAFF notes that recipes vary by region and household.

What the sources do not establish

The pages give no refrigeration instruction, shelf life, acidity or water-activity figure. They do not say the pickle ferments; sake lees are a product of fermentation, but nothing read shows a fermentation going on inside this mixture, so the page does not call it fermented. Treat the 2 to 3 days as the time to reach pungency, not as a keeping time, and keep the pickle cold unless you have a source that says otherwise.