FAQs

Although there is always going to be variation between batches, most studies and our own measurements suggest 900-1,100 μg total Vitamin K2 per 100 g of natto (that is, 250-300 μg per oz., or 450-500 μg per three-tablespoon serving.)

Although there is always going to be variation between batches, most studies suggest ~2,000 Fibrinolytic Units per three-tablespoon serving of natto.

Natto is a very stable fermented food product, so it is quite well protected and can be at ambient temperatures for a few days without any problem. However, for long term storage - Yes, refrigeration keeps your natto from over-ripening too quickly so that you can keep and enjoy them for many weeks/months.

When you receive your jars, you'll see a "Best By" ~4-5 weeks. Four jars is a month’s supply for health. This NOT an expiration date, rather a conservative estimate of when the natto remains tasting fresh (not over fermented) and retains maximum health benefits. The natto safe and edible for much longer.

Of course, you can freeze jars if you choose.  We dont recommend it because this will affect the taste/texture of the natto and will decrease its probiotic and nattokinase activity. Also, once thawed, the natto will age more rapidly than if it were never frozen.

Natto is fermented and meant to keep very well for several weeks. The "best by/sell by" date stickered on the bottom of each jar is NOT an expiration date. In sealed glass, our natto is perfectly good for at least one month after that.  In theory, the natto usually remains edible indefinitely but will gradually become overfermented, acquire pungent flavors, and decrease in some health benefits (probiotic, nattokinase activity). So we highly recommend finishing your natto within two months of the "best by" date.

Yes to both. Fresh natto comes with a lovely layer of white probiotic bacteria coating the soybeans. This may appear as a white ring around each bean, visible especially through the clear bottom of the jar. This is only good!  As the natto ages, very tiny distinct spots may appear on the beans - these are simply amino acids naturally crystallizing out over time. These are completely normal, harmless, and give a little "unami" crunch to the natto, which some people love.

Not really. Our natto is not vacuum packed, so there is little difference between a used but well-closed jar and an unopened one, as long as no outside contaminants are introduced.

Many scientific studies have been in agreement that 5 servings of natto (= 1 jar of our natto) per week is associated with best outcomes for bone, cardiovascular, cancer and longevity outcomes . (Link to Longevity blog article)in other words, aiming to finish one jar per week, per person is the goal. We recommend ordering what you can realistically finish within 2 months at a time. Like all living things, natto declines in vitality and potency with age.

Orders are typically processed within 1–2 business days. Delivery times vary by location, but most orders arrive within 3–7 business days. You’ll receive tracking details once your order ships.

No problem, fermented natto can go for many days without refrigeration. The real purpose of cooling is to extend the tasty and potent lifetime of this living food; it is not about safety. We actually make it by fermenting at up to 120F for a day, so hot temperatures are where natto is most comfortable. However, cooling it when possible will ensure that the natto does not overferment and ripen too quickly.

It is a marvel that door-to-door shipping across hundreds or even thousands of miles occurs so quickly. Only rarely do UPS/FedEx encounter delays or other problems. We want to reassure you that a day or two delay is not a problem for our natto.  If your order is delayed by >3 days after shipment, contact us and we will try to help you.

 100% YES.

We must receive order changes by 9am EST on the day of shipment at the latest. If the change does not alter the total basket price, we can do this.  If not, please cancel your order and reenter the revised request. Your cancelled order will be refunded.

Not yet.