The traditional form of sushi is fermented fish and rice, preserved with salt in a process that has been traced to Southeast Asia, where it remains popular today. The term sushi comes from an archaic grammatical form no longer used in other contexts; literally, “sushi” means “it’s sour”, a reflection of its historic fermented roots.
The science behind the fermentation of fish packed in rice is that the vinegar produced from fermenting rice breaks the fish down into amino acids. This results in one of the five basic tastes, called umami in Japanese. The oldest form of sushi in Japan, Narezushi still very closely resembles this process. In Japan, Narezushi evolved into Oshizushi and ultimately Edomae nigirizushi, which is what the world today, knows as “sushi.”
Contemporary Japanese sushi has little resemblance to the traditional lacto-fermented rice dish. Originally, when the fermented fish was taken out of the rice, only the fish was consumed and the fermented rice was discarded. The strong-tasting and -smelling funazushi, a kind of narezushi made near Lake Biwa in Japan, resembles the traditional fermented dish. Beginning in the Muromachi period (AD 1336–1573) of Japan, vinegar was added to the mixture for better taste and preservation. The vinegar accentuated the rice’s sourness, and was known to increase its life span, allowing the fermentation process to be shortened and eventually abandoned. In the following centuries, sushi in Osaka evolved into oshi-zushi. The seafood and rice were pressed using wooden (usually bamboo) molds. By the mid 18th century, this form of sushi had reached Edo (contemporary Tokyo).
The contemporary version, internationally known as “sushi,” was created by Hanaya Yohei (1799–1858) at the end of Edo period in Edo. The sushi invented by Hanaya was an early form of fast food that was not fermented (therefore prepared quickly) and could be eaten with one’s hands roadside or in a theatre. Originally, this sushi was known as Edomae zushi, because it used freshly caught fish in the Edo-mae (Edo Bay or Tokyo Bay). Though the fish used in modern sushi no longer usually comes from Tokyo Bay, it is still formally known as Edomae nigirizushi.
TYPES OF SUSHI
The common ingredient across all the different kinds of sushi is sushi rice. The variety in sushi arises from the different fillings and toppings, condiments, and the way these ingredients are put together. The same ingredients may be assembled in a traditional or a contemporary way, creating a very different final result. In spelling sushi its first letter s is replaced with z when a prefix is attached, as in nigirizushi, due to consonant mutation called rendaku in Japanese.
Nigirizushi (lit. hand-formed sushi) consists of an oblong mound of sushi rice that is pressed between the palms of the hands, usually with a bit of wasabi, and a topping draped over it. Toppings are typically fish such as salmon, tuna or other seafood. Certain toppings are typically bound to the rice with a thin strip of nori, most commonly octopus (tako), freshwater eel (unagi), sea eel (anago), squid (ika), and sweet egg (tamago). When ordered separately, nigiri is generally served in pairs. A sushi set may contain only one piece of each topping.
Makizushi (lit. rolled sushi) or makimono (lit. variety of rolls) is cylindrical piece, formed with the help of a bamboo mat, called a makisu. Makizushi is generally wrapped in nori, but can occasionally be found wrapped in a thin omelette, soy paper, cucumber, or parsley. Makizushi is usually cut into six or eight pieces, which constitutes a single roll order. Below are some common types of makizushi, but many other kinds exist.
Inarizushi (stuffed sushi) is a pouch of fried tofu filled with usually just sushi rice. It is named after the Shinto god Inari, who is believed to have a fondness for fried tofu. The pouch is normally fashioned as deep-fried tofu (abura age). Regional variations include pouches made of a thin omelette , fukusa-zushi or (chakin-zushi). It should not be confused with inari maki, which is a roll filled with flavored fried tofu. A very large version, sweeter than normal and often containing bits of carrot, is popular in Hawaii, where it is called “cone sushi.”
Sukeroku (name of a man in Edo period) is the combination set of inarizushi and makizushi, which is served as a single-portion takeout style sushi-pack. In a famous Kabuki play Sukeroku, a good-looking man Sukeroku is the lover of an Oiran courtesan named Agemaki (lit. fry for age and roll for maki). Age and maki which form her name correspond to fried tofu namely inari and makimono, respectively. One rumour of sukeroku-zushi is that takeout style packs of inarizushi and makizushi had served at performances of Sukeroku kabuki in Edo period. Sukeroku is a cheap sushi-pack and often vegetarian.
Chirashizushi ( lit. scattered sushi) is a bowl of sushi rice with other ingredients mixed in (also refers to barazushi). It is commonly eaten in Japan because it is filling, fast and easy to make. Chirashizushi most often varies regionally because it is eaten annually as a part of the Doll Festival, celebrated only during March in Japan. The ingredients are often chef’s choice. Edomae chirashizushi (Edo-style scattered sushi) is an uncooked ingredient that is arranged artfully on top of the sushi rice in a bowl.
Gomokuzushi (Kansai-style sushi) are cooked or uncooked ingredients mixed in the body of rice in a bowl.
Narezushi (lit. matured sushi) is a traditional form of fermented sushi. Skinned and gutted fish are stuffed with salt, placed in a wooden barrel, doused with salt again, and then weighed down with a heavy tsukemonoishi (pickling stone). As days pass, water seeps out and is removed. After six months this funazushi can be eaten, remaining edible for another six months or more.
The increasing popularity of sushi in North America as well as around the world has resulted in variations of sushi typically found in the West but rarely if at all in Japan. Such creations to suit the Western palate were initially fueled by the invention of the California roll. A wide variety of popular rolls has evolved since.