Handmade natto kit - 笑つと納豆手作りキット - 4本入り

$22.99
Best Before: Oct/30/2022

This kit allows you to make real natto by hand using natural bacteria.
We are particular about using rice straw grown in Nagano Prefecture with low agricultural chemicals, and use only high-quality rice straw that is also used for the sumo ring.
The soybeans are grown in Nagano Prefecture.
You can enjoy the delicious aroma of the straw and the original taste of the soybeans.
Please enjoy the authentic taste.

 

How to make traditional “Waratsuto Natto”

 

Contents in this kit : Dried soybeans (referred to as “soybeans” below), and rice straw bags (referred to as “waratsuto” below).

 

  1. Softening the soybeans

*We recommend using a steam cooker or a pressure cooker to soften the soybeans by using a steaming method, as it helps the soybeans retain the nutritional value and flavor. However, you can also use a regular saucepan. Please follow the instructions that match the method you use.

 

<With a steam cooker or a pressure cooker>

 

Give the soybeans a quick rinse with water to remove any dirt. Do not stir them while rinsing.

Soak them in plenty of water and leave over night (approximately for 12 hours) until the soybeans absorb the water.

 

If using a steam cooker, steam the soybeans for about 40 minutes. (With a pressure cooker, steam for about 10 minutes.)

 

<With a saucepan>

 

Give the soybeans a quick rinse with water to remove any dirt. Do not stir them while rinsing.

Soak them in plenty of water and leave over night (approximately for 12 hours) until the soybeans absorb the water.

 

Boil 10 times the amount of water to the dried soybeans. For example, 60g of the soybeans to 600ml of water. Once the water has boiled, pour the soybeans in and put a lid on. Cook them for about 30 minutes on a low heat.

 

*IMPORTANT : The cooking time can vary depending on the kind and size of the soybeans.

The soybeans should be soft enough to be squashed with fingers.

After fermentation, the soybeans will firm up a little.

 

  1. Sterilizing the “waratsuto”

 

Sterilize the “waratsuto” in boiling water for over 1 minute. Boil enough water so that the waratsuto can be completely covered.

 

Even with this process, the necessary natto forming bacteria known as “natto-kin” survives. The other bacteria die.

 

After sterilization, drain off the water from the waratsuto with a strainer.

 

*Be careful when handling the hot water.

 

  1. Packing the waratsuto

 

Remove the rubber band off the waratsuto and open it up as if making a boat shape (see fig ③-1). Then, pack in the cooked soybeans and close the straw completely.

 

The soybeans should be tightly incased by the straw (fig ③-2). Close the end with the rubber band.(fig ③-3)

 

  1. The fermentation process

 

Wrap the waratsuto with a piece of cloth or paper, such as newspaper. Make sure to wrap the waratsuto tightly so that the soybeans contained inside can touch the inside of the waratsuto without any spaces. Remember, the natto-kin bacteria need to pass from the straw to the beans. You can wrap a few waratsutos together if making more than one batch.

 

Put the wrapped up waratusto in a plastic bag. Do not seal the plastic bag. Leave the end of it open.(fig ④)

 

Keep everything at a temperature between 40℃ to 60℃ (104℉ to 140℉) for between 18 to 20 hours.

 

*IMPORTANT : The length of time required can vary depending on the season.

 

If the surface of the soybeans in the waratsuto have not developed a slight white coating, keep it warm longer.(fig⑤)

 

The key to making natto successfully is temperature management!

 

The natto-kin bacteria are the most active at temperatures between 40 to 45℃ (104 to 113℉) and soybeans ferment the best under those conditions. It does  not like temperatures over 60℃(140℉).

 

You can manage the temperature by using a hot water bottle, or a pet bottle filled with hot water, for example.

 

Ways to manage the temperature

 

  • Put the plastic bag containing the wrapped waratsuto in a styrofoam box or a cooler box with hot water bottles or PET bottles filled with hot water.
  • Wrap the plastic bag containing the wrapped waratsuto in a blanket with hot water bottles or PET bottles filled with hot water.
  • Put the plastic bag containing the wrapped waratsuto in a tea cosy with hot water bottles or PET bottles filled with hot water.

 

 

  1. Successful fermentation

 

If you find the soybeans stringy when you open the waratsuto and covered in a slight white coating, it means the soybeans are successfully fermented.(fig ⑤)

 

If each bean is covered with a slight white coating, that is the sign the natto-kin bacteria had spread to each bean.

 

  1. Stop fermenting and start the maturing process

 

Put the waratsuto containing the fermented soybeans (fig ⑤) in a refrigerator to stop the fermentation process. Leave it for between 1 to a maximum of 20 days to let the soybeans mature. The soybeans must stay in the waratsuto during this maturing process.

 

The longer it is kept in a refrigerator, the more mature and richer the soybean flavor becomes.

The taste of the soybeans changes from soybean flavor to natto flavor gradually.

The color of the soybeans also darkens if you let it sit longer.

If you are a natto beginner, try a maturing period of only a few days.

If you are a natto lover, try to mature the soybeans for over a week!

Experiment and find your own favorite taste! Enjoy your home made natto!