Hiyamugi is a type of noodle made of wheat flour. They are eaten in Japan, and they are distributed mainly as dried noodles. They are often eaten chilled, and they are commonly available as a cool summer noodle dish.
For the dried noodles, a dough is made by mixing wheat flour, salt and water, and kneading it thoroughly. The dough is cut into narrow strips and dried. The ones made by a machine using this manufacturing process is classified as machine-made noodles. The ones made by the manufacturing process of mixing wheat flour, salt and water, kneading the dough thoroughly, stretching and gathering the dough in bundles by sprinkling the dough with starch, cooking oil or wheat flour, then drying and ageing is classified as tenobe (hand-stretched) hiyamugi. In this case, the noodles also need to meet the "Japan Agricultural Standards for hand-stretched dried noodles."
According to the "Quality Labeling Standard for Dried Noodles" of the Japan Agricultural Standards (JAS), machine-made noodles should be between 1.3 mm and 1.7 mm in diameter (it is also possible to use the label 'thin udon noodles' in cases where this standard is satisfied). Incidentally, somen noodles and udon noodles are classified as under 1.3 mm and over 1.7 mm in diameter, respectively. In the case of hand-stretched noodles, the same standards apply to hiyamugi and somen noodles.
Those shaped into rods with diameters under 1.7 mm are classified as 'hand-stretched hiyamugi noodles' or 'hand-stretched somen noodles.'
Incidentally, those shaped into rods with diameters over 1.7 mm are classified as 'hand-stretched udon noodles.'
The production quantity of dried noodles was once maintained at 80,000 tons until late 1960's/early 1970's, but it decreased quickly from the latter half of 1970's. During the decade starting from the 1980's there was a temporary increase in the amount produced.. However, the decreasing trend did not stop even in the Heisei period (1989 -), and during the decade starting in 1998 the production amount fell to 20,000 tons, which was one quarter of the amount produced in the decade starting in 1965. In terms of production ratio among dried noodles, hiyamugi noodles maintained its ranking next to somen and udon noodles. However, its ranking was surpassed by soba (buckwheat) noodles in 1993, and the production ratio is following a yearly decreasing trend every.
Regarding fresh and boiled noodles, according to the "Fair Competition Codes concerning labeling of fresh noodles," "under these codes, 'udon noodles' refer to noodles produced after adding water to wheat flour and kneading the mixture, or to those that have been processed after the noodles are made, regardless of whether they are named hiramen (flat noodles), hiyamugi, somen or others."
Therefore, according to these codes, 'hiyamugi' is classified as 'udon', and in a narrow sense it can be interpreted that 'fresh- or boiled-type hiyamugi noodles are a type of udon noodles.'
However, it is stated in a separate section that "the labeling can be changed to one that is not misunderstood by the general consumer." Therefore, the use of the label "hiyamugi" is also allowed, and in reality, products that comply with these codes are made and sold. Because of these cases, in a broad sense (in general), it can be said that "fresh- and boiled-type hiyamugi noodles also exist." Incidentally, although few in number, there are establishments that provide hand-made hiyamugi noodles.
Before machine-made noodles became common it was possible to distinguish somen noodles from hiyamugi noodles because the cross-section of the somen noodles was round due to the fact that the dough was made thin by the hand-stretching process, and the cross-section of the hiyamugi noodles was square because the dough was flattened and then cut into narrow strips. However, hiyamugi noodles nowadays are made by almost the same manufacturing method as that of the somen noodles, and this method of distinguishing the noodles became inappropriate. Furthermore, in general, they are treated as a type of somen noodles rather than udon noodles because they are eaten in the same manner as somen noodles, and also because their texture is similar to that of the somen noodles.
There is a widely accepted theory that the culture of eating thin noodles in Japan began with the muginawa (wheat rope) that was introduced from China during the early Nara period. However, the specific shape of the noodles are not understood well, and it has been considered for a long time that they were a type of hand-stretched or hand-made noodle. Somen noodles similar in style to the present-day somen noodles became widely available during the Muromachi period. Noodles made by a new method of cutting with a knife, such as a cleaver (cut noodles), appear in the written records from that period. In "Oraimono" (a primary textbook in the style of exchanging of letters), which said to have been written by Kanera ICHIJO, there is a passage that states that somen noodles are steamed, and kirimugi noodles (cold noodles) are cold washed. It can be seen that at that time, somen noodles were mainly eaten hot after they were steamed, while kirimugi noodles were usually eaten chilled. Furthermore, words such as kirimen (cut noodles), kirimugi (cut wheat noodles), hiyamugi, reimen (Korean-style cold noodles) and kirireimen (cold cut noodles) are frequently mentioned beside kirimugi in diaries from the 15th century. They are clearly distinguished from 'udon' noodles, which also began to appear frequently during the same period. Hiyamugi noodles are cut noodles that have a shape different from the udon noodles, and because they are also discussed in conjunction with somen noodles, it can be assumed that they are cut noodles whose shape is close to that of somen noodles. Furthermore, because the pronunciation of the kanji characters for 'chilled wheat' is undoubtedly 'hiyamugi,' it seems that during this period the concept of 'cut noodles similar to somen = hiyamugi' was already born. After some time had passed it was written in the 1697 honsosho (book of herbs) "Honcho shokkan" (mirror of food in our country) that udon noodles were items for cold times and hiyamugi noodles were good for hot times. Therefore, it can be assumed that the custom of eating udon and hiyamugi noodles according to the seasons was already established during this period.
Additionally, there is a theory that states that there were noodles called 'kirimugi' that were made by kneading wheat flour and water, cut into strips, then boiled and eaten, and a distinction was made between those eaten warm as 'udon' and those eaten chilled as 'hiyamugi.'
Furthermore, there is a theory stating that while udon noodles are thick in order to retain heat, hiyamugi noodles gradually became thin because they are eaten at cooler temperature.
How they are eaten
As with somen noodles, they are commonly eaten with a dipping sauce after having been boiled, chilled in ice water or running water, and then rubbed and rinsed in order to remove the sticky starch. Salt is not added to the water for boiling. This is so that the salt can be removed from the noodles. Because the noodles are thin, they readily take up other flavors, and it is therefore necessary to wash the hands in water as thoroughly as possible in order to avoid oil from the hands coming into contact with them. The salty-sweet dipping sauce is made of ingredients including soy sauce, dashi stock and sugar. It is preferable to make it the day before eating the noodles. There are cases in which sesame sauce is used as a dipping sauce or added to the dipping sauce. In some cases garnishes such as braised shiitake mushrooms and julienned strips of thin omelet are used. Chopped spring onions, grated ginger, sesame seeds and Japanese ginger are used as condiments. It is possible to eat the noodles in the same way as the somen noodles, and 'The way Somen noodles are eaten' should be referred to for details.
Unlike somen noodles, hiyamugi noodles are said not to be well known in western Japan. Because hiyamugi noodles often boil in just about the same amount of time as the soba noodles, hiyamugi noodles are often served instead of somen noodles during summer in soba noodle shops in and around Tokyo.
There are cases in which several strands of colored noodles, such as red or green ones, are included among the hiyamugi noodles (there are cases where they are also included in somen noodles). This is because noodle factories add colored noodles to the bundles of hiyamugi noodles. They were used to tell the difference between somen noodles and hiyamugi noodles. This tradition was often seen in the regions around Kanto area (Tokyo) until the latter half of the 1980's. However, it gradually became less common, and the majority of the hiyamugi noodles became white during the 1990's. On the other hand, however, some manufacturers such as Ibo no Ito continue the tradition even to this day. Because children get excited when they see colored noodles, they have come to sometimes be added to somen noodles in recent years.
In Hokkaido, green hiyamugi noodles called 'green men,' made by mixing in powdered chlorella, are widely distributed.
In Yamanashi Prefecture, there are regions in which noodles such as hiyamugi are called 'odara' or 'ozara' because of the Kai Province dialect.