# Best Koji Starter Spores Source: https://fermentnest.com/best/best-koji-starter-spores Updated: 2026-10-06 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 Koji is the starting point for miso, shoyu, amazake and shio koji, and the spores you buy decide what is possible. Strains are selected for different jobs: some are bred for enzyme output on rice, others for soybeans or barley, and a few produce more aroma than sugar. Packaging varies from small foil sachets to bulk tins, sometimes cut with flour to make spreading easier. Viability depends on age and cold storage, so purchase date matters. We weighed strain suitability, how clearly each supplier documents intended uses and dosage, packaging size, and cold-chain handling. A general-purpose rice koji strain suits first attempts at amazake and shio koji. Soybean-oriented strains are the pick if miso or shoyu is the goal. Small sachets fit occasional makers, and bulk tins are worth it for monthly growers with freezer space to keep the rest viable. ## Picks ### 1. Kawachi Yellow Koji Starter Spores, 0.53oz (15g) Tane-koji oryzae Mold Spore Starter for Japanese Fermented Foods, Miso Soy Sauce Our score: 8.6/10 (Fit for the job 9/10 · Features and specs 8/10 · Build and materials 9/10 · Value 8/10) Kawachi's yellow koji starter spores, 0.53oz (15g) of tane-koji oryzae for miso, soy sauce and Japanese ferments. Pros: - Yellow koji spores are the classic choice for miso and soy sauce - Kawachi is a long-established Japanese koji spore producer - 15g provides enough spores for several inoculations Cons: - Growing koji needs precise heat and humidity control - Spores are for making koji, so rice or barley must be prepared Details: https://fermentnest.com/product/B0DKHWLPT9 ### 2. Hishiroku Kairyou Chohaku-kin Koji Starter Spores 0.7 oz (20g) Sachet Our score: 8.4/10 (Fit for the job 9/10 · Features and specs 8/10 · Build and materials 8/10 · Value 8/10) Hishiroku Kairyou Chohaku-kin koji spores in a 20 g powder sachet, sold by Kawashimaya. An Aspergillus oryzae starter for white rice koji, miso, amazake and sake. Pros: - Made by Hishiroku of Kyoto, described in the listing as a 300-year-old specialist koji maker. - One 20 g sachet is rated to make up to 15 kg (33 lb) of rice koji, more than most home batches need. - Powder format lets you adjust the dose, and the listing suggests using 2 to 3 times more for better results. Cons: - Spores only: you still need steamed rice and a warm, humid incubation setup to grow koji. - A 20 g sachet is a lot for an occasional maker, so leftover spores need careful cool, dry storage. Details: https://fermentnest.com/product/B0FNNBJGPD ### 3. Hishiroku Chouhaku-kin Koji Starter Spores 0.7oz (20g) Sachet (Set of 3) Our score: 8.4/10 (Fit for the job 9/10 · Features and specs 8/10 · Build and materials 8/10 · Value 8/10) Three 20g (0.7 oz) sachets of Hishiroku Chouhaku-kin koji starter spores, described as the whitest and most versatile type, for rice koji, amazake, shio koji and white miso. Pros: - Each 20g sachet is stated to yield up to 15kg (33 lbs) of rice koji, so the set of 3 covers many batches. - Made by Hishiroku, which the listing describes as a 300-year-old specialist koji manufacturer in Kyoto. - Powder in sachets, with guidance to use 2x or 3x the spores when you want a stronger result. Cons: - A set of 3 sachets is more than an occasional koji maker needs, and a single sachet is the smaller way in. - No storage instructions or shelf life in the listing, which matters when three sachets are used over time. Details: https://fermentnest.com/product/B0FYD4F1RG ### 4. Hishiroku Kairyou Chohaku-kin Koji Starter Spores 0.7 oz (20g) (Set of 3) Our score: 8.1/10 (Fit for the job 9/10 · Features and specs 7/10 · Build and materials 8/10 · Value 8/10) Three 20g (0.7 oz) sachets of Hishiroku Kairyou Chohaku-kin koji starter spores (Aspergillus oryzae) from Kyoto, sold for white rice koji, miso, sake and amazake. Pros: - Stated yield of up to 15kg (33 lbs) of rice koji per 20g sachet, which makes three sachets a long-running supply. - From Hishiroku in Kyoto, described in the listing as a specialist koji manufacturer with 300 years of history. - Easy-to-measure powder in sachets, and the listing notes the spore quantity can be adjusted per batch. Cons: - The listing does not explain how Kairyou differs from the standard Chouhaku-kin, so the choice is unclear. - Three sachets is a lot of spores for a first try, and a single sachet costs less up front. Details: https://fermentnest.com/product/B0FYDCQ4KC ### 5. Shirayuri Koji (Aspergillus oryzae) Spores Gluten-Free Vegan - 200g/8oz Our score: 8.0/10 (Fit for the job 8/10 · Features and specs 7/10 · Build and materials 8/10 · Value 9/10) Shirayuri koji (Aspergillus oryzae) spores, gluten-free and vegan, in a large 200g/8oz bag for heavy use. Pros: - 200g bag supplies many batches for miso and shio koji makers - Shirayuri is a known strain for rice koji - Gluten-Free Vegan label suits plant-based kitchens Cons: - Large quantity may lose viability before a hobbyist uses it all - Bulk bag needs careful cold, dry storage Details: https://fermentnest.com/product/B084L71PM3 ### 6. Hishiroku Chouhaku-kin Koji Starter Spores 0.7oz (20g) Sachet Our score: 8.0/10 (Fit for the job 8/10 · Features and specs 8/10 · Build and materials 8/10 · Value 8/10) Hishiroku Chouhaku-kin koji spores in a 20 g sachet. The listing calls it the whitest and most versatile strain, aimed at rice koji, amazake, shio koji and white miso. Pros: - Described as keeping its white color with strong fermentation ability, useful for pale ferments like white miso. - One 20 g sachet is rated for up to 15 kg (33 lb) of rice koji, enough for many home batches. - Produced by Hishiroku in Kyoto and sold as a powder that is easy to measure out. Cons: - Only 20 g per sachet, so anyone making koji every week may prefer a larger pack. - Very close to the Kairyou Chohaku-kin sachet from the same maker, so most kitchens need only one of the two. Details: https://fermentnest.com/product/B0FNNFBCHJ ### 7. Shiragiku Koji (Aspergillus oryzae) Spores Gluten-Free Vegan - 10g/0.35oz Our score: 7.6/10 (Fit for the job 8/10 · Features and specs 7/10 · Build and materials 8/10 · Value 7/10) Shiragiku koji (Aspergillus oryzae) spores, gluten-free and vegan, in a 10g/0.35oz packet. Pros: - Shiragiku strain is popular for sweet rice koji and amazake - Gluten-Free Vegan label suits plant-based fermenters - 10g size is a manageable amount for home experiments Cons: - Small packet is quickly used by frequent koji makers - Success depends on steady warm, humid incubation Details: https://fermentnest.com/product/B07XJ7X4KN ### 8. Kawachi White Koji Starter Spores, 0.53oz (15g) Tane-koji Mold Spore Starter for Japanese Fermented Foods, sake miso soy sauce amazake Our score: 6.7/10 (Fit for the job 8/10 · Features and specs 5/10 · Build and materials 7/10 · Value 6/10) Kawachi White Koji starter spores (tane-koji) in a 15g (0.53 oz) packet, listed for Japanese ferments such as sake, miso, soy sauce and amazake. Pros: - A white koji starter in the Kawachi line, an alternative to the yellow Kawachi koji also covered in this guide. - 15g packet is a small-batch size, so there is less to store between koji-making sessions. - Title lists sake, miso, soy sauce and amazake as intended uses, the range most home koji makers work in. Cons: - The listing has a single generic bullet, with no stated yield per gram, strain details or dosing guidance. - At 15g it is a small packet, so the cost per gram runs higher than the multi-sachet sets. Details: https://fermentnest.com/product/B0GNM1F5C3 As an Amazon Associate I earn from qualifying purchases.