Only sometimes. Many soba noodles mix buckwheat with wheat flour. 100% buckwheat soba has no wheat, but sauces vary and menus don't list everything, so ask.

Why is soba served cold?

Cold soba shows off the buckwheat's nutty taste and firm bite. It comes on a bamboo mat with a soy-dashi dipping sauce, scallions and wasabi.

Udon vs soba: what's the difference?

Udon is thick, chewy wheat noodles with a mild taste, while soba is thin buckwheat noodles that taste nutty and earthy, often served cold with a dipping sauce.

Udon

Very light

Indulgent

Subtle

Big punch

Mellow

Zingy

Thick, soft and bouncy, mild and comforting.

Soba

Very light

Indulgent

Subtle

Big punch

Mellow

Zingy

Thin, firm buckwheat noodles with a nutty, earthy taste.

The real difference

Udon is made from wheat flour, cut thick, and tastes mostly of what it's served in. Soba is made with buckwheat, often mixed with some wheat, cut thin and gray-brown, with a nutty, earthy taste of its own. Both come hot in broth or cold with a dipping sauce, but soba is the classic cold one.

Side by side

UdonSoba

Made fromWheat flourBuckwheat, often with some wheat

NoodlesThick, white, chewyThin, brownish, firm

TastesMild, softNutty, earthy

Classic wayHot in dashi brothCold with a dipping sauce

Which to order

Order udon if you want a soft, slurpy, comforting bowl.
Order soba if you want something lighter with more flavor in the noodle itself.

Quick questions

Is soba gluten-free?: Only sometimes. Many soba noodles mix buckwheat with wheat flour. 100% buckwheat soba has no wheat, but sauces vary and menus don't list everything, so ask.
Why is soba served cold?: Cold soba shows off the buckwheat's nutty taste and firm bite. It comes on a bamboo mat with a soy-dashi dipping sauce, scallions and wasabi.