Soba

Allergens at a glance

• UsuallyBuckwheatThe noodles are buckwheat flour; cooking water and steam carry it to other dishes.
• UsuallyGlutenMost soba is blended with wheat flour, and the sauce contains soy sauce.
• UsuallyFishThe dipping sauce and hot broth are made with bonito dashi.
• UsuallySoySoy sauce is the base of the dipping sauce (tsuyu) and the hot broth.
• SometimesEggsRaw egg toppings, tempura batter, and egg used as a binder in some noodles.
• SometimesCrustaceansPrawn tempura toppings and kakiage; shared frying oil.

Usually in the standard recipe. Often in many versions. Sometimes in some kitchens, or a cross-contact risk.

Diets

• Rarely vegetarian: the tsuyu is almost always bonito dashi.
• Not suitable for coeliacs (celiacs): most noodles contain wheat and the tsuyu contains wheat-brewed soy sauce.
• Halal is uncommon: the tsuyu usually contains mirin.

Recipes change from kitchen to kitchen. If you have an allergy, confirm every ingredient with the restaurant before you order.

What is soba?

Soba is a thin, grey-brown noodle made from buckwheat, eaten cold with a dipping sauce or hot in broth. It's one of Japan's oldest everyday foods, sold everywhere from standing counters at train stations to specialist shops that mill their own flour. In Japan the word soba on its own means buckwheat noodles.

What's in it

Pure buckwheat dough is crumbly, so most soba is bound with wheat flour. The ratio is often on the menu:

• Juwari (十割): 100% buckwheat.
• Ni-hachi (二八): 80% buckwheat, 20% wheat, the most common ratio at soba shops.
• Cheap and instant soba can be mostly wheat.

The sauce, tsuyu, is dashi with soy sauce and mirin. Classic dishes:

• Zaru or mori soba: cold noodles on a bamboo tray, with tsuyu, spring onion and wasabi.
• Kake soba: hot noodles in broth.
• Tempura soba (tensoba): with prawn tempura or a kakiage fritter.
• Kitsune soba: with sweet fried tofu; tsukimi soba: with a raw egg.

Allergens and diets

Buckwheat is the headline. It's a common cause of severe reactions in Japan and Korea, and it's on Japan's mandatory allergen list. It's not related to wheat. Exposure isn't limited to eating the noodles: shops often boil udon in the same water, and flour dust and steam can carry buckwheat in a busy kitchen. Some soba restaurants serve soba-yu, the cooking water, at the end of the meal. If you have a buckwheat allergy, avoid soba shops rather than ordering around the noodles.

For gluten, juwari soba removes the wheat from the noodle, but the tsuyu uses soy sauce brewed with wheat, and the same equipment handles wheat noodles. Ask about the sauce as well as the flour.

The tsuyu is always soy and almost always fish from bonito dashi. Toppings bring the rest: tempura adds egg batter and crustaceans, tsukimi adds raw egg, and a few makers use egg in the dough.

On the menu

Soba is written 蕎麦, そば or sometimes 生蕎麦 (kisoba, fresh soba). Look for:

• ざる zaru / もり mori: cold
• かけ kake: hot broth
• 天ぷらそば tenpura soba, 天ざる tenzaru
• きつね kitsune: fried tofu
• 月見 tsukimi: raw egg
• 十割 juwari, 二八 ni-hachi

Beware 焼きそば yakisoba and 中華そば chūka soba: both are wheat noodles, not buckwheat.

How to eat it

For cold soba, dip a small mouthful into the tsuyu and slurp. When you finish, you may be offered soba-yu to pour into the leftover sauce and drink.

Last checked 1 November 2026. Spotted something wrong? Email support@inventum.com.au.