Soba: a beginner's guide to buckwheat noodles

Ramen is loud and udon is generous. Soba is the one that asks you to slow down. A good plate of cold buckwheat noodles actually tastes of something: earthy, a little nutty, faintly of the field. Of all Japan's noodles, I think it's the one that most rewards paying attention.

It's also the one with the most to decode. The menu has numbers on it, the sauce comes in a cup, and at the end someone may bring you a pot of hot, cloudy water. Here's what's going on.

A noodle that isn't wheat

Soba (蕎麦) means buckwheat, and by extension the noodles made from it. Despite its English name, buckwheat isn't a kind of wheat, or even a grass. It's the seed of a flowering plant related to rhubarb and sorrel, and it's naturally free of gluten.

That last point is the soba maker's challenge. Gluten is what holds wheat dough together, and without it buckwheat dough is crumbly and quick to tear. That's why many soba noodles include some wheat flour as a binder, and why noodles made from pure buckwheat are seen as a test of skill.

A practical note: because of that added wheat, most soba is not gluten-free. Buckwheat itself is also a well-known allergen, and in Japan it's one of the ingredients that must be declared on packaged food. If you're allergic, take it seriously; in some kitchens, soba and udon share the same pot of water.

Juwari, nihachi and the numbers on the menu

Two words on menus and shop signs describe the flour blend.

• Juwari (十割) means "ten out of ten": the noodles are 100% buckwheat. Expect a deeper aroma, a slightly coarser texture and noodles that break more easily.
• Nihachi (二八) means "two-eight": roughly two parts wheat flour to eight parts buckwheat. The wheat makes the noodles smoother and more elastic, and many people consider it the classic balance.

Which is better? I don't think either wins. Juwari tastes more of the grain; nihachi slides down more easily and holds its shape. I'd choose juwari when I want to taste buckwheat, and nihachi when I want the full pleasure of a long, cold slurp.

Colour varies too. Flour milled from the pale heart of the seed makes elegant, almost white noodles, a style called sarashina (更科). Grinding in more of the outer layers gives darker, speckled noodles with a stronger, earthier flavour.

Cold or hot: what to order

Soba lovers often start cold, because chilling shows off the noodle's texture and aroma.

• Mori (もり) and zaru (ざる) are the classic cold orders: chilled noodles on a bamboo mat with a cup of tsuyu (つゆ), a dipping sauce of dashi, soy sauce and mirin. Many shops top zaru with strips of nori seaweed and leave mori plain, though the distinction varies.
• Kake (かけ) is the basic hot bowl: noodles in a broth that's lighter than the dipping sauce. From there come the toppings, such as kitsune with sweet simmered fried tofu, tempura, or tsukimi, "moon-viewing", with a raw egg cracked on top.

For cold soba, the condiments usually arrive on a little plate: wasabi and negi (ネギ), finely sliced green onion. Stir them into the tsuyu to taste. Hot bowls are often joined by shichimi (七味), a seven-spice chilli blend, on the table.

An old Tokyo habit is to dip only the bottom part of each mouthful into the sauce, so the buckwheat isn't drowned. I think it's a good habit. And yes, slurp: it's normal, and our guide to slurping has more on that.

The soba-yu ritual

When your noodles are gone, a server may bring a small lacquered pot of cloudy hot liquid. This is soba-yu (蕎麦湯), the water the noodles were cooked in.

Pour some into your leftover dipping sauce, stir, and drink it like a soup. The salty sauce turns gentle and warming, and the starchy water carries one last trace of buckwheat. If it hasn't appeared at a shop serving cold soba, it's usually fine to ask.

I love this little ritual. It's the one moment in a Japanese noodle meal when finishing the sauce isn't just allowed, it's the point.

Four regional bowls

Buckwheat copes well with cool, mountainous country, and many regions have their own way with it. Izumo, Togakushi and wanko soba are often grouped together as Japan's three great soba.

• Izumo soba (出雲そば), Shimane: dark, fragrant noodles served in warigo (割子), small round lacquered dishes stacked in tiers. You pour a little sauce straight over the top dish, eat, then tip what's left into the next.
• Togakushi soba (戸隠そば), Nagano: from the mountain shrine area of Togakushi, in a prefecture long famous for buckwheat. It's traditionally served cold on a flat bamboo basket, often arranged in neat little bundles.
• Wanko soba (わんこそば), Iwate: a server tosses mouthful-sized portions into your bowl, one after another, and keeps going until you put the lid on. Part meal, part endurance sport.
• Nishin soba (にしんそば), Kyoto: hot soba topped with a fillet of dried herring, simmered until sweet and savoury. A proper winter comfort.

Soba is also the noodle many Japanese households eat on New Year's Eve, and our piece on toshikoshi soba tells that story. When you're ready to try it, find soba shops on the map.

Soba doesn't shout, and that's its charm. Give it a quiet counter and a few minutes of attention, and a plate of plain grey-brown noodles turns out to have a great deal to say.