Natto is a simple, basic Japanese food made from fermented soybeans . This unusual and traditional food has been known in Japan for two thousand years or more, and has been now recognized as a food beneficial to the health of the consumer. The health benefits are considered preventative, for example , to prevent intestinal diseases, obesity, osteoporosis, heart attacks, and even cancer. It is recognized that the “bacillus natto”, the bacteria that causes the fermentation also creates amino acids, enzymes, and vitamins which are beneficial to human health; two compounds created in the fermentation, specifically pyrazine and nattokinase , dissolve and even prevent blood clots, which are well known to cause stroke.
Soybeans themselves, as a crop that improves soil condition by the legume nitrogen-fixing process, grow well on marginal quality lands. High in protein and oils, soybeans are a highly desirable crop.
Clearly, there are many reasons to make Natto and use it as a food source. In a hungry world, soybeans are easily produced. Vegans , healthy-food addicts and environmentally concerned people alike will appreciate the fact that Natto is a probiotic, natural food, and contains high quantities of vitamin K, and the essential vitamin B12 , a vitamin relatively absent in a meat-free diet, but very plentiful in Natto.
The “sticky threads” of Natto “resin” are capable of absorbing at least 5000 times it’s weight in water and is therefore a fascinating subject for research projects of the future. Projects involving this unique resin include industrial projects, greening deserts, and agricultural applications.
Natto as a food, is unique with a distinctive, strong odour and it is sticky, which some people may not appreciate. The taste may be undesirable to some people, much as the flavour of blue cheese is an acquired taste. DO try come commercial Natto first, before you try making it, so you will have an idea what it is supposed to “be like”.
Reportedly, if you like strongly flavoured cheeses, such as blue cheese, you may indeed appreciate the fine flavour of Natto. Here is a recipe to make your own !
HOW TO MAKE YOUR OWN NATTO:
Traditionally, soybeans were cooked, steamed and wrapped in rice straw that naturally provided the “bacillus nato” (bacteria) that creates the special flavour during the fermentation. The rice straw was boiled and used to wrap the soaked, steamed soybeans for the duration of the fermentation . No rice straw? No problem.
Today it is much simpler, you can buy Natto bacillus culture at some health food stores much as you can purchase specialized wine yeasts or other highly specialized food ingredients.
* Important :
When making Natto, it is VERY important to maintain cleanliness. Sterilize the utensils used to avoid contamination by other bacterial sources.
For equipment, you will need :
-A stainless steel or enameled pot and a glass or ceramic casserole dish.
-A strainer ( Colander)
-An insulated “box”. (Here you can be creative; the ” box” may be your kitchen oven, a Styrofoam picnic cooler, or any equivalent insulated, warm space that will maintain a constant, warm temperature. )
- 500 grams of soybeans. Choose a smaller variety of Soybeans if possible.
-1/4 tsp. of salt (approximately) Use natural or pickling salt rather than iodized salt.
-1 tsp. Brown sugar (white optional)
-1 tsp. Molasses (optional)
-About 0.1 grams of Bacillus Natto powder. (Alternatively, a package of commercially prepared Natto)
- 20 ml of boiled water.
*Wash the soybeans thoroughly, remove any foreign particles and all dirt !
*Soak the soybeans overnight in about 4 times the volume of water.
The beans will swell up substantially. It will take at least 10 or twelve hours. Do not remove the skins. If the water begins to froth a bit, the beans have been soaked adequately. Strain the beans with the colander and rinse them carefully.
*Steam the soybeans for five to six hours to cook them, or cook them gently, in water. Alternatively, place them in a pressure-cooker for 15 minutes. Allow the pressure cooker to cool completely before opening it !
Like any beans, if you can squash a soybean easily between your fingers, they are cooked adequately.
* Make the following “Natto” Bacillus seeding mixture separately:
Mix the boiled water with one-tenth of a gram of Natto bacillus powder, or alternatively, with a couple of tablespoon of commercially prepared natto, which will provide the bacillus you need.
Mix in the salt, sugar, and molasses. This mixture feeds the Natto bacillus and encourages it to grow.
*Drain the soybeans well. Gently mix in the “seeding mixture”, or spread the beans evenly in a glass casserole dish and sprinkle the mixture evenly over the top of the beans. Do NOT mash the beans. Cover the casserole with aluminum foil, but poke a few holes in it to allow SOME air to enter.
If you do not allow any air into the container, it will become very strong smelling !
If you allow TOO MUCH air, it will dry out. Experiment. Maintain humidity necessary by placing an open dish containing water in the box.
*Place the covered casserole dish in the “fermenting box” with a “warm” heat source; a light bulb, 40 or 60 watt will likely suffice. The object is to maintain an even temperature between 100 degrees F and 108 degrees F. (37C to 42 C approx.) in a moderately high humidity environment for approximately 16-24 hours to complete the fermentation.
*Ferment the Natto by holding that temperature for up to 24 hours. If you want a stronger flavour, turn off the heat after 24 hours, but do not mix the Natto or disturb the process for another 24 hours.
*Take the fermented beans out of the pan . It may have a whitish cast’ on it if the humidity was too high, and the surface will be cracked and dried out if there was insufficient humidity.
Refrigerate the Natto for a few days, perhaps a week, preferably in a clean, covered replacement container, to age it a bit.
Try it! Hopefully your batch turned out well ! Stir it a bit, you will see that it becomes a bit stringy as you stir it. If it gets stringy, that is a sign that the Natto bacillus worked.
Reportedly, the way to test your Natto is to add some soy sauce and mix it well. If it forms strings (“neba neba” in Japanese) again when you stir it a few hours later, it is fine .
It should NOT taste sour. Keep the finished product refrigerated ..
Eat Natto with rice, vegetables, in a sandwich, or add to soups and other dishes. Try soya sauce and mustards as condiments. Enjoy!
Cautions, Extra Hints and Disclaimer :
-DO try some commercial Natto first so you know have a basic idea what Natto should taste like, as opposed to spoilage. Results can also vary with different brands of commercially made natto as the seed culture
-Use a little of your Natto and FREEZE the rest !
-If your Natto turned out well, you can even use some of it to re-seed a new batch!
-This is an organic, fermented food, much like fermented pickles, cheese, sauerkraut and other similar, naturally made foods and may be easily contaminated by other spoilage bacteria. Like cheeses, some batches turn out better tasting than others !
If your process was not sanitary, highly variable and questionable results CAN be achieved so DO exercise caution and care ! Nobody has any control over the quality of the process except the person making it