Is Natto Gluten-Free? The Complete Celiac Guide
Natto — Japan's famous fermented soybeans — is one of the few traditional Japanese foods that is naturally gluten-free. The catch? The sauce packet included in every commercial pack almost certainly contains wheat-based soy sauce. Here is how to eat natto safely.
The tare packet is the risk
Plain natto is safe. The tare (タレ) sauce sachet bundled with every commercial pack contains wheat-based soy sauce (shoyu). Always discard it and use gluten-free tamari or plain salt instead. The karashi (mustard) sachet is usually wheat-free, but check the allergen label for 小麦 (komugi / wheat) to be certain.
Natto at a Glance
Plain natto is safe
Fermented soybeans + Bacillus subtilis natto culture = naturally gluten-free. No wheat, barley, or rye in the base product.
The tare packet is NOT safe
The small sauce sachet included with commercial packs contains wheat-based soy sauce (shoyu). Discard it and use tamari or salt.
Available everywhere
Sold at all supermarkets and convenience stores (7-Eleven, FamilyMart, Lawson) for 100–200 yen per 3-pack. Also served at hotel breakfast buffets.
How to Eat Natto Safely
Natto + plain rice (納豆ご飯)
The classic breakfast combination. Steamed white or brown rice with natto on top. Use tamari instead of the included tare. Completely gluten-free and nutritious.
Natto + tamari soy sauce (タマリ醤油)
Replace the included tare with a small splash of gluten-free tamari. Kikkoman's GF tamari is widely available at Seijo Ishii, Bio-Ral, and online. San-J tamari is another reliable brand.
Natto + salt (塩)
The simplest seasoning: a pinch of sea salt highlights the natural umami of natto without any risk of gluten cross-contact.
Natto with raw egg (卵かけ納豆ご飯)
A popular variation in Japan — mix natto with a raw egg over hot rice. The egg is naturally gluten-free. Still swap the tare for tamari.
Natto miso soup (納豆汁)
Some regions (especially Yamagata and Tohoku) serve natto stirred into miso soup. The natto is safe but confirm the miso is rice-based (kome-miso) and the dashi does not contain soy sauce.
Natto at hotel breakfast buffets
Most Japanese hotel breakfast buffets offer natto in individual cups. The tare is typically pre-mixed or provided separately — ask staff to bring it un-mixed, then use your own tamari.
Hidden Gluten Risks with Natto
Tare sauce packet (タレ)
Every commercial natto pack includes a small tare sachet. This condiment is almost universally made with wheat-based soy sauce (shoyu). It looks innocuous but is the main gluten risk.
Discard the tare entirely. Season with gluten-free tamari (look for 'タマリ' or 'グルテンフリー醤油' on the label) or plain salt.
Pre-seasoned natto varieties (味付け納豆)
Some natto products come pre-seasoned with tare already mixed in or with flavored coatings (kimchi, wasabi, mentaiko). These flavorings may contain wheat-based soy sauce.
Choose plain natto (プレーン納豆) and check the ingredient label for 小麦 (komugi). The plain variety is the safest choice.
Natto rolls at sushi restaurants (納豆巻き)
Natto maki (sushi rolls with natto) are served with standard soy sauce (shoyu), which contains wheat. The rice may also be seasoned with rice vinegar mixed with soy sauce at some restaurants.
Bring your own tamari packet. Ask staff: 'Tamari wa arimasu ka?' (タマリはありますか?). If they cannot confirm the rice seasoning is GF, avoid the roll.
Restaurant natto dishes (納豆料理)
Cooked dishes containing natto — such as natto pasta, natto fried rice, or natto tempura — typically add soy sauce or other wheat-containing seasonings during cooking.
For cooked natto dishes, explicitly ask about wheat content: 'Komugi wa haitte imasu ka?' (小麦は入っていますか?). At izakayas, natto in plain cups (not cooked) is the safer order.
What Is Natto?
Natto (納豆) is a traditional Japanese food made by fermenting soybeans with Bacillus subtilis var. natto, a beneficial bacteria. It has been a staple of Japanese cuisine for over 1,000 years, particularly in eastern Japan (Kanto and Tohoku regions).
Characteristics
- •Strong, pungent aroma — often compared to aged cheese
- •Sticky, stringy texture formed by fermentation by-products
- •Deep earthy, slightly bitter umami flavor
- •Nutritional powerhouse: high in protein, vitamin K2, probiotics, and nattokinase
Gluten-Free Status
Plain natto contains only soybeans (大豆) and Bacillus subtilis natto starter culture. No wheat, barley, rye, or any gluten-containing grain is involved in the fermentation process. It is classified as a naturally gluten-free food in the same category as edamame, tofu, and miso made from rice or chickpeas.
Buying Natto at Convenience Stores
All major Japanese convenience stores stock natto year-round. Here is what to look for and what to avoid.
Standard 3-pack (3パック入り) — 100–200 yen
The most common format. Look for plain (プレーン) varieties. Discard the tare sachet. Brands to look for: Takaokaya (高岡屋), Mito no Tenpei (水戸のてんぺい), Okame (おかめ).
Check the allergen label (アレルゲン表示)
The ingredient list on the pack will show the 小麦 (komugi / wheat) allergen marker if the tare contains wheat — it almost always does. The soybeans section (大豆) will not list wheat.
Avoid flavored varieties
Kimchi natto, wasabi natto, and sesame natto often have additional seasonings that may contain wheat. Stick to plain natto to be safe.
Karashi mustard sachet
The small yellow karashi packet included with many packs is typically made from mustard powder and vinegar only — gluten-free. Still check the allergen label for 小麦 to confirm.
Practical Tips for Celiac Travelers
Carry your own tamari
Buy a small bottle of gluten-free tamari at Seijo Ishii, Bio-Ral, or specialty food stores in Japan. Kikkoman and San-J both make GF tamari available in Japan. With your own tamari, you can safely eat natto anywhere — supermarkets, convenience stores, even hotel breakfasts.
Hotel breakfast natto
Most Japanese hotel buffets serve natto. The tare is usually provided in a small dish beside the natto cups. Ask hotel staff to bring you un-seasoned natto ('tare nashi de onegaishimasu' / タレなしでお願いします) and season it yourself with tamari or salt.
Read the label for 小麦
On any natto pack, find the allergen section (アレルゲン) and look for 小麦 (komugi / wheat). If it appears in the tare ingredients, discard the packet. If no wheat is listed anywhere on the label, the entire product may be safe — but this is rare; most tare contains shoyu.
Natto at izakayas
Natto is a common izakaya menu item, typically served in a cup with the tare on the side. Ask for it 'tare nashi' (タレなし / without sauce) and bring your own tamari. Natto in izakayas is usually served plain, not pre-cooked, making it a reliable safe option.
Stir before eating
Natto is traditionally stirred vigorously (50–100 times is the Japanese custom) before eating to develop the sticky texture and mellow the flavor. This is purely about texture and taste — stirring does not affect gluten safety.
Use your allergy card
For any restaurant where natto is cooked into a dish, show your Japanese allergy card explaining your wheat allergy. Ask: 'Komugi arerugii ga arimasu. Komugi wa haitte imasu ka?' (小麦アレルギーがあります。小麦は入っていますか?).
Essential Japanese Phrases for Natto
タレなしでお願いします
Tare nashi de onegaishimasu
Without the sauce packet, please
タマリはありますか？
Tamari wa arimasu ka?
Do you have tamari (GF soy sauce)?
小麦アレルギーがあります
Komugi arerugii ga arimasu
I have a wheat allergy
小麦は入っていますか？
Komugi wa haitte imasu ka?
Does this contain wheat?
このタレに小麦は入っていますか？
Kono tare ni komugi wa haitte imasu ka?
Does this sauce packet contain wheat?
プレーンの納豆をください
Purein no natto wo kudasai
Please give me plain natto
グルテンフリーのタマリ醤油を持っています
Guruten furii no tamari shouyu wo motte imasu
I have gluten-free tamari soy sauce
Plan Your Japan Trip
Find Hotels with Japanese Breakfast in Tokyo
Many Tokyo hotels offer traditional Japanese breakfast buffets with natto, rice, and miso soup. Book on Booking.com for free cancellation on most rooms.
Browse Tokyo hotels →Book a Japanese Cooking Class
Learn to prepare traditional Japanese breakfast dishes including natto, tamagoyaki, and miso soup in a hands-on cooking class with local chefs.
Explore cooking classes →Links above are affiliate links. We may earn a commission at no extra cost to you.
Before You Go
Two things every traveler to Japan should sort out in advance — staying connected and booking the experiences that fill up fastest.
Get a Japan eSIM
Land with data already working. An eSIM lets you look up restaurants, translate menus, and show your allergy card to staff — no SIM swap, no pocket Wi-Fi to return.
Browse Japan eSIM plans →Book food tours & experiences
Skip-the-line tickets, market walks, and small-group food tours sell out weeks ahead. Reserve the celiac-friendly ones early.
Find experiences in Japan →We may earn a commission from these links at no extra cost to you. It helps keep this guide free.
FAQ
Is natto gluten-free?
Plain natto (fermented soybeans) is naturally gluten-free — it contains only soybeans and Bacillus subtilis natto culture, with no wheat. However, the small tare (sauce) packet included with every commercial pack almost always contains wheat-based soy sauce (shoyu). To eat natto safely with celiac disease, discard the included tare and season with gluten-free tamari or salt instead.
What is in the natto sauce packet?
The tare packet bundled with most commercial natto contains soy sauce (shoyu), which is brewed from wheat and soybeans. Some packs also include a karashi (Japanese mustard) sachet, which is generally wheat-free, but always check the label for the komugi (小麦 / wheat) allergen marker before using either packet.
Where can I buy natto in Japan?
Natto is sold at virtually every Japanese supermarket and most convenience stores (7-Eleven, FamilyMart, Lawson) in packs of 3 styrofoam cups. It is usually found in the refrigerated tofu and dairy aisle. Price is typically 100–200 yen for a 3-pack. Many hotel breakfast buffets also serve natto.