# Best Natto Making Supplies and Starters Source: https://fermentnest.com/best/best-natto-making-supplies Updated: 2026-09-15 Publisher: Ferment Nest. Our score is an editorial rating out of 10 (fit 35%, features 25%, build 20%, value 20%), not a customer rating. Method: https://fermentnest.com/how-we-research#our-score Natto is a short list of requirements applied strictly: cooked soybeans, Bacillus subtilis natto spores, and warmth held steady for around a day. The spores are the part you cannot improvise, and they come as powder in tiny quantities or as a starter portion of finished natto. Beyond culture, what varies is the gear: shallow trays or containers that let the beans breathe, a cover that holds humidity without sealing, and an incubator or heat mat. We compared spore packaging and dosing, how clear the instructions were, tray design and airflow, and whether incubation gear held temperature without drying the batch. A small spore packet suits anyone testing natto for the first time, since a little goes a long way. Bundled kits with trays and culture reduce guesswork. Vented containers are worth a set if you make natto often, and a proofing box is the upgrade later. ## Picks ### 1. Kawashimaya Natto Starter Powder 3g (0.1oz), To Make 10-30kg of Homemade Natto, Bacillus Subtilis From Soybean Extract Our score: 8.6/10 (Fit for the job 9/10 · Features and specs 8/10 · Build and materials 8/10 · Value 9/10) Kawashimaya's natto starter powder, 3g (0.1oz) of Bacillus subtilis to make 10-30kg of homemade natto. Pros: - 3g of powder makes 10-30kg of natto, a very high yield - Bacillus Subtilis from soybean extract is the classic natto culture - Tiny pack is easy to store in the fridge or freezer Cons: - Very small doses are hard to measure without a micro scoop - Natto needs careful temperature and humidity control Details: https://fermentnest.com/product/B09325M42X ### 2. Kawashimaya Natto Starter Spores Powder, Made From Soybean Extract (30g) Our score: 8.1/10 (Fit for the job 9/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) Kawashimaya's natto starter spores powder made from soybean extract, a 30g pack for homemade natto. Pros: - 30g pack supplies many batches of homemade natto - Soybean Extract base keeps the starter aligned with traditional natto - Kawashimaya specializes in Japanese fermentation ingredients Cons: - Needs steady heat around a full day, so an incubator helps - Larger pack than casual natto makers are likely to use Details: https://fermentnest.com/product/B09Q87YSZN ### 3. Signature Soy NON-GMO Soybeans for Natto 5 Lbs, Fresh Crop Small Size Soybean Our score: 8.1/10 (Fit for the job 9/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) Signature Soy's NON-GMO soybeans for natto, 5 Lbs of fresh crop small size soybeans. Pros: - Small Size soybeans ferment evenly and give classic natto texture - NON-GMO fresh crop beans suit careful home fermenters - 5 Lbs bag supplies many batches of homemade natto Cons: - Beans need overnight soaking and long steaming before use - No starter is included, so natto spores are a separate purchase Details: https://fermentnest.com/product/B094GHMT6C ### 4. Signature Soy NON-GMO Soybeans for Natto 20 Lbs, Fresh Crop Small Size Soybean Our score: 8.0/10 (Fit for the job 8/10 · Features and specs 7/10 · Build and materials 8/10 · Value 9/10) Signature Soy's NON-GMO soybeans for natto, a 20 Lbs bulk bag of fresh crop small size soybeans. Pros: - 20 Lbs bulk bag lowers the cost per batch for regular natto makers - Small Size beans are the traditional choice for natto - Also works for tempeh, soy milk and other soybean projects Cons: - Heavy bag needs airtight storage to keep pests away - Far more beans than an occasional natto maker needs Details: https://fermentnest.com/product/B0150DMF9A ### 5. Japanese Natto Starter Spores (Nattomoto) - 3g, 100% Organic Soybean Extract, Product of Japan Our score: 7.8/10 (Fit for the job 8/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) Japanese natto starter spores (nattomoto), 3g of 100% organic soybean extract, a product of Japan. Pros: - 100% Organic soybean extract base suits organic kitchens - Product of Japan nattomoto uses a traditional starter - 3g pack goes a long way for many soybean batches Cons: - Compare seller ratings and feedback before choosing a supplier - Tiny doses need careful measuring for consistent natto Details: https://fermentnest.com/product/B07DK2D289 ### 6. Cultures For Health Natto Starter Spores, Traditional Soybean Japanese Food, Gluten Free Vegan Our score: 7.6/10 (Fit for the job 8/10 · Features and specs 7/10 · Build and materials 8/10 · Value 7/10) Cultures For Health's natto starter spores for traditional Japanese soybean natto, gluten free and vegan. Pros: - Cultures For Health offers detailed natto guides for beginners - Gluten Free Vegan spores suit plant-based fermenters - Traditional culture recreates the classic sticky natto texture Cons: - Confirm how many batches the spores cover before comparing prices - Natto aroma is strong and not everyone enjoys it Details: https://fermentnest.com/product/B0BGQH6QGG ### 7. Jesscasday 10g Natto Powder Bacillus Subtilis Nattokinase Agent for Making Sticky Fermented Soy Beans Our score: 6.8/10 (Fit for the job 7/10 · Features and specs 7/10 · Build and materials 6/10 · Value 7/10) Jesscasday's 10g natto powder, a Bacillus subtilis nattokinase agent for making sticky fermented soy beans. Pros: - 10g pack gives a good number of batches for regular natto eaters - Bacillus Subtilis agent creates the signature sticky strings - Powder form mixes easily with warm cooked beans Cons: - Listing is not clearly Japanese sourced like established starter brands - Instructions may be limited compared with specialist sellers Details: https://fermentnest.com/product/B0CNWJ3HQ3 ### 8. DIIOOMIEEU 10Pcs Nattomoto Starter Japanese Natto Fermented Soybeans Powder, Bacillus Subtilis Active Natto Our score: 6.8/10 (Fit for the job 7/10 · Features and specs 7/10 · Build and materials 6/10 · Value 7/10) DIIOOMIEEU's 10Pcs nattomoto starter packets, active natto powder with Bacillus subtilis for fermented soybeans. Pros: - 10Pcs pre-portioned packets remove guesswork about dosing - Active Natto powder begins fermenting cooked beans quickly - Individual packets keep unused starter sealed Cons: - Unfamiliar brand name gives little assurance of quality - Confirm the yield per packet on the packaging before your first use Details: https://fermentnest.com/product/B0F5VVPP5R As an Amazon Associate I earn from qualifying purchases.