Shiso ( Japanese: 紫蘇 or シソ) is the more widely used name of the Asian culinary herb Perilla frutescens var. crispa, belonging to the mint family.
This herb was previously known as the “beefsteak plant”, a mostly obsolete name. It is also sometimes referred to by its genus name “Perilla”, which is ambiguous, as it is also inclusive of the so-called “wild sesame” variety, P. frutescens var. frutescens, which is devoid of the distinctive shiso fragrance.
Shiso is a perennial plant that may be cultivated as an annual in temperate climates, and occurs in both red- (or purple-) leaved and green forms. There are also frilly, ruffled-leaved forms called chirimen-jiso and forms that are red only on top, called katamen-jiso.
The Japanese name shiso (紫蘇, シソ) is a loan word from Chinese zisu (Chinese: 紫苏; pinyin: zǐsū; Wade–Giles: tsu-su), whose first character 「紫(shi, murasaki)」 means “purple”.
Traditionally in Japan shiso denoted the purple-red form. In recent years green is considered typical, and red considered atypical.
The purple-red type may be known as akajiso (赤ジソ/紅ジソ “red shiso”). The quintessential use is for colouring the pickled plum, or Umeboshi. The shiso leaf turns bright red when it reacts with the umezu, the vinegary brine that wells up from the plums after being pickled in their vats. The red pigment is identified as the Perilla anthocyanin, aka shisonin. The mature red leaves are not very amenable to use as a raw salad leaf. But germinated sprouts me-jiso (芽ジソ) have been used for years as garnish to accent a Japanese dish such as a plate of sashimi. Also used are the hanaho (花穂 flower cluster) or hojiso, which are sprigs or stalks studded with tiny-cupped flowers and forming seeds. The tiny pellets of buds and seed pods can be scraped off using the chopstick or fingers and mixed into the soy sauce dip to add the distinct spicy flavour. The sprouts and flowerheads of the green variety are also used the same way.
Bunches of green shiso leaves packaged in styrofoam trays are now familiar sights on the supermarket shelves in Japan, as well as in Japanese food markets in the West. But production in earnest as leafy herb did not begin until the 1960s.
One anecdote is that around 1961, a certain cooperative or guild of tsuma (ツマ “garnish”) commodities based in Shizuoka Prefecture picked large-sized green leaves of shiso and shipped them out to the Osaka market, and gained popularity, so that ōba (大葉 “big leaf”) became the trade name for bunches of picked green leaves forever after.
A dissenting account places its origin in the city of Toyohashi, Aichi, the foremost ōba-producer in the country, and claims Toyohashi’s Greenhouse Horticultural Agricultural Cooperative (豊橋園芸農協) experimented with planting c. 1955, and around 1962 started merchandising the leaf part as Ōba, and in 1963 organised “cooperative sorting and sales” of the crop (kyōsen kyōhan (共選・共販), analogous to cranberry cooperatives in the US). By c. 1970, they achieved year-round production.
See Perilla for the herbal and spice uses of the species in different countries.
A whole leaf of green shiso is often used as a receptacle to hold wasabi, or various tsuma (garnishes) and ken (daikon radishes, etc., sliced into fine threads). It seems to have superseded baran, the serrated green plastic film, named after the Aspidistra plant, that graced takeout sushi boxes in bygone days.
The green leaf can be chopped up and used as herb or condiments for an assortment of cold dishes such as:
- cold noodles (hiyamugi, sōmen)
- cold tofu (known as Hiyayakko)
- tataki and namerō[ja]
Chopped leaves can be used to flavour any number of fillings or batter to be cooked, for use in warm dishes. A whole leaf battered only on the obverse side is made into tempura. Whole leaves are often combined with shrimp or other fried items.
Red leaves are used for making pickled plum (umeboshi) as mentioned, but this is no longer a yearly chore undertaken by the average household. Red shiso is used to colour shiba-zuke, a type of pickled eggplant (also cucumber, myoga, shiso seeds may be used), Kyoto specialty.
The seed pods or berries of the shiso are also salted and preserved as a sort of spice. They can be combined with fine slivers of daikon, for instance, to make a simple salad. One source from the 1960s says that oil expressed from shiso seeds was once used for deep-frying purposes.
The name yukari refers to dried and pulverized red-shiso flakes, and has passed into the common tongue as a generic term, even though Mishima Foods Co. insists it is the proprietary name for its products. The term yukari-no-iro has signified the colour purple since the olden days, based on a poem in the Kokin Wakashū about a murasaki or gromwell blooming in Musashino (old name for Tokyo area). Moreover, the term Murasaki-no-yukari has long been used as an alias for Lady Murasaki’s famous romance of the shining prince.