Making Natto
Preserved cooking illustration

Making Natto

Making Natto

Making Natto

Fermented soy beans with a funky aroma and earthy flavor! While often served with a bowl of rice, soy sauce, spicy mustard and an egg; try mixing it with just about any grain and condiment for a fast, highly nutritious, protein-rich and satisfying meal.

INGREDIENTS 2 lbs (~4 cups) Natto (small variety) soybeans 2 teaspoons of pre-boiled water (boiled in order to sterilize) 1 spoonful (0.1g) dried culture or 1ml of liquid natto starter culture

Rinse the soybeans and soak for 9-12 hours (longer soaking time recommended in winter months) at a ratio of 3 parts water to 1 part soybeans. Drain the beans in a colander or sieve. Fill a large pot with fresh water and simmer for about 9 hours. (If using a pressure cooker or Instant Pot, follow manufacturer’s instructions for cooking beans).

Drain the cooked beans and return them to the pot. Dissolve the culture into 1 Tablespoon of pre-boiled water (to sterilize). Immediately pour the natto spore solution you just made over the beans while the beans are still hot. (Don’t worry about the hot temperature, the heat activates the cultures). Stir the beans and water mixture thoroughly. Carefully spread in a thin even layer approximately 1/2 - 1” deep in a glass casseroles dish. Stretch aluminum foil across the top of the casserole dish, crimping the edges and sealing tightly. While holding it taut, poke a series of air holes. (Alternatively, you can use several 4 oz glass jars with a layer of muslin over the top of the jars and place a tight-fitting lid on top, in lieu of a baking dish).

Incubate at 100º using our Brod & Taylor Proofer or following another Fermentation Incubation Hack and allow the natto to ferment for 20 -24 hours making sure that the 100ºF temperature is maintained. After 20-24 hours check for slimy film and texture. Ferment a few hours longer if needed, until slimy-film is in full form. After the fermentation period let the natto cool for a couple of hours with the cover still on. Then, the natto can be stored in a sealed container in the refrigerator. Enjoy within about 6 weeks. (Some like to let it age in the fridge for an additional week before eating to develop stronger flavors). Smaller portions can be stored in the freezer and thawed for later use.

Please use these recipes and information as guidance for your home fermenting endeavors. This is not medical advice nor should it replace the advice of a health care professional. Fermented foods often have a sour but clean aroma and flavor. Never consume anything that smells or tastes unpleasant. Preserved does not take responsibility for your own success and/or failures in fermentation. We have made our best effort to share up-to-date and safe techniques. However, the risks of cooking and fermenting are inherent. You are responsible for the results of your efforts and the safety of your own food in your particular location and kitchen. Thank you for your interest in preserving a closer connection to your food.