Hegi soba uses a seaweed also used in weaving
Hegi soba uses funori seaweed as a binder. The agriculture ministry's regional food record associates it with Uonuma and describes the wooden rectangular tray called a hegi on which it is served. Funori was also a familiar material used to size threads in weaving.
Using a seaweed from textile work in noodles connects local work with local food. It also gives the noodles their smooth feel and springy texture.
Small bundles are part of hegi soba's presentation
The noodles are gathered into individual portions and arranged on the tray. Alongside the binder, this presentation helps define hegi soba. The ministry also records a Uonuma custom of serving mustard rather than wasabi.
Tsugaru soba starts with sobagaki
Tsugaru soba uses soybeans as a binder, as described in the agriculture ministry's traditional food guide. The Hirosaki tourism association describes cooling sobagaki, a buckwheat paste, in water overnight, mixing in soybean flour to make noodles, and resting them for another night. The dough passes through a cooked-paste and cooling stage before it is cut into noodles.
An interview with a restaurant published by Aomori tourism information also describes resting sobagaki before adding soybean flour. Shops and households vary, but soybeans and resting time are central to this traditional method.
Hegi soba combines funori with its small-portion presentation. Tsugaru soba adds soybeans and takes time to prepare the dough. Both are buckwheat noodles, but their ingredients and hands-on methods differ.