, in Japanese cuisine, are the eggs or the ovaries (egg skeins) of the Pacific herring (Japanese: ) that have been salted or dried.
Overview
Kazunoko is a product processed by removing the roe sacs (or "egg skeins") from female herrings intact in its shape, then preserving by sun-drying (hoshi kazunoko) or by salting or brining (shio kazunoko). The eggs are individually tiny, but together they form oblong clusters measuring approximately long and wide.
The kazunoko, symbolizing fertility, has been a staple of the osechi assortment of food for the New Year. From around 1955, domestic herring catches fell sharply for Japan (mostly only caught around Hokkaido in the north), and nearly all supplies now depend on imports, mostly from the Pacific coasts of Canada and Alaska, cf. Fig. 1, line graph of annual catch tonnage, imports, egg supply. but also including the use of Atlantic herring. and Table 7 "Processing suitabilities of Atlantic herring, by production area 大西洋ニシンの生産地別加工適性について" A technique for bleaching into uniform gold color was established, and the lucrative commodity earned the nickname of "yellow dia[mond]".
A subtype is the or "spawn on kelp", which are Pacific herring eggs laid on various seaweed regarded as "kelp", now harvested mostly in British Columbia, Canada.
Historically, the oldest records of kazunoko in Japan date back to the 15th and 16th centuries, and they were served, for example to Toyotomi Hideyoshi, during the spring season (Cf. below). The harvest of kazunoko from herring occurs in the spring, but the dried product was being sold as a New Year's season item by the end of the 17th century. The history of its production overlaps with the history of producing dried for food, which came into full force around Kyōho (1716–36) with the availability of salt up north, and later the production of kasu or fishmeal from early 19th century onwards.
The traditional harvesting of spores on kelp by natives, including the use of hemlock branches for the purpose, is surveyed (Cf. ).
There are various socio-economic issues which concerns Pacific herring fishing overall, with regards to native fishing grounds being overtaken by modern mass commercialized production,, p. 17ff. But aspects particular to herring roe have been taken up below, e.g., the "kazukono ledger" to record the debts to be worked off by Ainu women. Also, North American herring fishing since the 1960s have has principally been aimed at harvesting the kazunoko for the Japanese market, waste/sustainability issues have been raised (cf. also ).
Etymology Both "kazunoko" and the archaic kadonoko occur in medieval or post-medieval writings and also written in forms such as
There are two or three etymological hypotheses that have been presented.
The derivation of kazunoko as the corrupted form of kado no ko, where kado is the old name for herring, is the generally accepted etymology according to some sources. This explanation is already attested in the published 1697. The entry under kado in the Honchō shokkan clarifies the pronunciation of the character by the supply the phonetic reading as . It goes on to state that has been phonetically written as . Even beyond the Edo Period, kado or kado iwashi still survives in dialect as local name for herring, even though nishin is the standard Japanese term.
The alternate etymological theory holds that kazunoko may well have derived from the literal verbatim meaning of 'child of numbers/numerousness', as had been suggested by 's (1830/1834), and in fact, early usage writes the word as kazunoko (cf. below).
A third theory is discernible in the Edo Period essay (1830), which mentions that kazunoko was known by the alias in contemporary (onna kotoba), juxtaposed with the information that Muromachi period literature wrote of kozukozu (cod organ) as a New Year's dish. The connection between these two (similarly sounding) terms as synonymous (cognates?) are made in the dictionary.
There is speculation that Japanese kado must have derived from some Ainu word, but the known Ainu word for "herring" is heroki, (with variant spellings), and linguist rejects this hypothesis.
Japanese cuisine
Kazunoko marketed in Japan fall into these groups: , and .
Only limited supplies of the dried are now manufactured. The flavored type using Atlantic roe have been characterized as "secondary market", or even "substitute" products by American sources (but see further discussion below).
Kazunoko a standard part of New Year's fare called osechi, and are soy-sauce marinaded to keep for days (or made into kasuzuke).
Kitaōji Rosanjin, eminent gourmet connoisseur and restaurateur, commented in his time that although raw or salted kazunoko was becoming available, dried kazunoko reconstituted with water was the best, taste-wise (essay, loosely translated "Kazunoko is about eating the sound", 1930). While it is typically served topped with bonito flakes and splashed with soy sauce, Rosanjin insists on not letting the sauce seep in too much; his rule also opposes introducing other flavors such as miso or sakekasu, or pickling/marinating in soy sauce. -Aozora bunko However, there is also the opposite opinion, that the dried kazunoko is "more delicious after letting the soy sauce soak in well"".
Matsumaezuke is a soy-pickled dish that typically contains chunks of kazunoko in the mix of julienned dried squid (surume) and kombu seaweed. s.v. "", p. 378 The addition of kazunoko allegedly only dates back to 1929, as an arrangement on what was originally a squid and kelp recipe.
The kazunoko is known for its texture or mouthfeel (crunchiness), the sound of biting into it described onomatopoeically as puchi puchi (cf. ) The Atlantic herring is deemed overall to have less crunchiness, so that they are largely consigned to becoming "flavored kazunoko" or a side dish (sōzai, equivalent to okazu). But Atlantic herring of some regions are made into the normal salted/brined variety (Cf. ).
The "komochi kombu" (aka kazunoko kombu) or "spawn on kelp" may be eaten on its own as a delicacy, or sliced up and used for sushi. and can command very high prices.
Quality assessment by region
Of the diminished Japanese herring catch in Hokkaido, only a minuscule fraction now gets used for exploiting the eggs. and Table 6 "Processing suitabilities of Pacific herring, by production area 太平洋ニシンの生産地別加工適性について" According to one comparative study, the Canada Pacific herring roe taken in British Columbia, or Alaskan roe harvested in Sitka or Kah Shakes Cove produce quality eggs, suited for salted (or even dried).
Atlantic herring roe according to some sources are considered to be limper. But they are not always being downgraded as "flavored kazunoko" quality, and some are considered fit for making into regular salted/brined kazunoko, particularly roes from Baltic and North Sea area fish. Thus the Baltic group (subspecies C. harengus menbrus) has been rated best among Atlantic species fit to be made into salted (shio kazunoko), as are the roes originating in Scotland (Shetlands), Ireland, and Netherlands have been Other than texture, viscosity (ability to bind together into a lump) is another criterion for quality, and eggs that fall apart easily is a disqualifying factor for manufacturing whole salted kazunoko.
The Atlantic herring, with the crunchiness (hagotae) somewhat wanting. And one study does concur the Atlantic types do not solidify as firmly, and are mostly processed as flavored kazunoko, but generalizations aside, the same study assesses the Baltic Sea Baltic catches (subspecies C. harengus menbrus) to be superlative in Atlantic, and these do get used for making salted kazunoko, even though the individual egg size is smaller (half by weight) according to other studies.
Nutritional value
A basic nutritional value and energy assessment has been made in a study of Edo Period foods, including kazunoko.
While kazunoko is high in cholesterol (as are fish roe in general), it also contains a high concentration of EPA and DHA fatty acids, known to reduce cholesterol levels. While herring is classed as an aozakana (lit. 'blue fish') consisting of fish considered good sources of omega-3 fatty acids, herring (or 'blue fish' in general) had been blacklisted as food to avoid for gout (gouty arthritis) patients due to purine content, though recent studies and guideline have muted the warning against 'blue fish', unless it is the dried or semi-dried himono type. But even though fish roe are generally to be avoided by gout sufferers, kazunoko is listed as containing very low concentrations of purine (<50 mg per 100g). Similar dieteary cautions and recommendations apply to those diagnosed with hyperuricemia, which is considered a preliminary stage towards gout.
History
In Japan, the custom of serving kazunoko for the New Year's season may date back to the Muromachi Period, according to some sources., s.v. "", p. 100 As aforementioned, there is the record of being served for the New Year according to the mid-Muromachi Period (Kanshō 6/1465), but this was actually cod's innards, probably the male cod's milt; howbeit, kozukozu has been treated as an alias for kazunoko by some dictionaries. The is attested to be the offspring(eggs) of the kado fish in an even earlier source (1454) which names it alongside the kurukuru (alias of kozukozu).
The name kazunoko also appears on the menus in later Muromachi period and Azuchi–Momoyama period documents.
It was offered as menu item during a visit by the Ashikaga shogunate to Echizen Province in 1568 (Eiroku 11), recorded in .
Later Toyotomi Hideyoshi was offered kazunoko on the menu when he was hosted by the Maeda clan of Kaga Province, as recorded in the of the 4th lunar month of Bunroku 3 (1594).
Edo Period
In the Edo Period, documents from the Kanbun era (1661–1673) for instance indicate shipments of dried herring and kazunoko occurring out of Ezo (Hokkaido).
The work (published 1697) attests that kazunoko was an item that circulated in the market during the lunar 12th and 1st month.
The repertoire of herring products was limited until salt became readily available locally and products such as appeared, around the Kyōho] Period. Production of the migaki nishin and kazunoko (for food), as well as dried milt, gills (and guts) for fertilizer are depicted in an 18th-century series of folding screen pictures entitled . Damaged (crumbled) kazunoko pieces were also relegated to becoming fertilizer material. Note that kasu or shimekasu (herring meal squeezed of oil) was not manufactured at this time, and would not commence until several decades later in the early 19th century, or perhaps earlier.
Matsumae clan records from Kyōho 2/1717 show that kazunoko was being loaded on ships from various provinces, while the dried milt and herring for fertilizer headed particularly to the Chūgoku region provinces and Ōmi Province.
The kazunoko was all part of the fertilizer trade according to some commentators,: "Nishin ya kazunoko, shirako ga hiroku Chūgoku ya Ōmi suji ni renpi [nishin+koe] to shite urarete ita 鰊や数の子、白子が広く中国や近江筋に鰊肥として売られていた" though other sources regard the kazunoko as food item. The document also records that (eggs that were pried apart, re-gathered and molded into rectangles, cf. below) was being sent as or tribute to the Shogunate. The kazunoko during the Tokugawa period were packed in straw (俵), then at Osaka unpacked and re-boxed.