Miso Master Miso Paste

Miso Master miso should be refrigerated as soon as it arrives home from the store, or once it is delivered after ordering online.  Please do not wait until the product is opened to put it in the refrigerator.

Our short-term miso varieties (Chickpea, Mellow White, and Sweet White) are fermented using temperature control at 80 degrees F, while the long-term varieties (Brown Rice, Country Barley, and Traditional Red) are fermented in wooden vessels at room temperature for a minimum of 4 seasons. Each recipe has its own ideal fermentation time. Once that time is reached, miso should be refrigerated to halt further fermentation. In a nutshell, refrigeration helps to create a consistent product, rather than delay spoilage. We found that it takes around 3 days in warmer weather or around 5 days in cooler weather for the miso to “wake up” and start fermenting again, which is why we feel confident shipping miso unrefrigerated. Being exposed for a short period of time to warm temperatures has no ill effect on our product and only in very rare cases has caused a slight increase in fermenting the product further. We recommend refrigeration upon receipt to further extend the shelf life of our miso and ensure no increase in fermentation. Some of our miso flavors are fermented for 1 year or more, so transit time (even in warm months) is not an issue.

The only ingredients handled in our miso-making facility are the ones in our certified organic, non-GMO verified miso: barley, chickpeas, koji spores, rice (brown and white), sea salt, and soybeans.

Thank you for your interest in Miso Master products!  All of our miso varieties except our Country Barley Miso are third-party certified gluten free by NSF.  

Miso should be good until the best-by date on the bottom of the container, regardless of when it’s opened. That said, it’s common for customers to find that their miso lasts well beyond the best-by date too!

We changed the aging period for both our Country Barley and Brown Rice misos from two years to one year.  This is due to changes in demand for our other varieties.  Our plan is to return to a two year aging process at some point in the future but we don’t have specific timing yet.

Customers will occasionally see packaging for these varieties that refers to a 2 year aging time.  We made the decision to use these already-existing containers in order to avoid generating more plastic waste into our environment.

The ingredients used in our miso are cooked prior to aging.

We do not add any MSG when making our miso. That said, we do not test for free glutamate or glutamic acid and cannot say for certain if those are present.

Lectin/isoflavone/probiotics are not something we currently test our products for, although that may change in the future.

Miso shares traits with other fermented foods such as yogurt, sauerkraut, and kimchi and is known for its beneficial bacteria and probiotic content. Another helpful property in our soy-based varieties is isoflavones. According to the National Cancer Institute, isoflavones can reduce cancer cells’ ability to form new blood vessels and by attacking their reproduction mechanism.

Miso is a wonderfully versatile ingredient. Check out some of our delicious miso recipes or our guide on How to Use Miso Paste.

Due to the salt content, miso put in a freezer doesn’t freeze – it just gets really cold! If you’re short on refrigerator space it should be fine to store miso in the freezer temporarily until you get some room available in the refrigerator. Miso kept in the refrigerator is good until the best-before date regardless of when it is opened, and it’s not unusual for customers to find it stays good beyond that date too! Please note that freezer temperatures can kill the beneficial bacteria that live in miso.

There are no animal ingredients in any of our miso products.

We unfortunately can’t cite any studies proving that miso is safe for pregnancy.  Anecdotally, it appears that miso is safe to eat during pregnancy in limited quantities due to the high sodium content.  Everyone is different so we suggest pregnant customers check with their medical provider for a personalized recommendation.


Our Haiku teas do not have an expiration date but do have a best-before date. This is 2 years after the date of manufacture. The manufacture date is the first 5 numbers in a code printed in black ink on the side of the box. The first 2 numbers are the year, and the subsequent 3 numbers are the Julian date, which refers to the number of days in the year rather than day of the month. For example, a code with 21001 was manufactured on January 1st, 2021, while a code with 21365 was manufactured on December 31st, 2021. If your tea is within 2 years of its manufacture date, you can be assured you are getting the best representation of the product.

Yes! Our haiku teabags are compostable.

Tea bags may be sensitive to the odors around them. We recommend storing your tea away from strong scents or chemicals

Emerald Cove

We take great care in the sourcing of our Emerald Cove sea vegetables. To that end, we send a sample of each crop year to an independent laboratory for testing for heavy metals and radiation. The results consistently measure in the parts per million.

For detailed information on specific testing please use our contact us form and submit your question under "product questions".

Our nori used to be certified kosher but is no longer. The product has not changed. What has changed is the standard our kosher certifier uses when evaluating the product. The evaluation process now includes examination by microscope for crustaceous substances, when it hadn't before. As you may already know, our Emerald Cove nori is grown in the open ocean. As one could imagine it is impossible to separate the animals that live in the sea - including crustaceans - from the nori crop. Because we cannot guarantee that we will pass the new microscope test 100% of the time, we made the decision to cease kosher certification for our nori.

The white powder sometimes seen on our kombu is due to naturally-occurring glutamic acid. Since this is a natural product, there is variation in how much is present in each pack of kombu.  While always delicious, kombu with visible glutamic acid is thought to impart an extra umami flavor!

Emperor’s Kitchen

Our garlic and ginger products are good for 2 years unopened, and should be used within 6 months of opening. These products should be refrigerated after opening.

Sushi Sonic

With this product, it's vital to allow the flavor to "bloom". Mix your wasabi paste with very cold water. Cover the container with plastic wrap or a lid and refrigerate while the flavor develops. Allow it to develop for at least 15 minutes after mixing with water. Heat and flavor will continue to develop when refrigerated and covered. Test the paste and if more heat is desired allow it to continue to sit covered and refrigerated for up to a full day. Once the paste is in contact with the air the heat will dissipate, so it is best served in small portions after being freshly made and allowed to bloom. Freeze any unused powder to maintain optimal freshness.

If you have purchased our 100% Wasabi Powder you may not get the same taste you are accustomed to finding in restaurant-style wasabi paste. Our 51% Wasabi Powder is the same blend as you find in restaurants and may be more to your liking. For optimum preparation and storage of your wasabi powder, see our FAQ "What is the best way to prepare wasabi paste?".


All USDA Organic products must meet federal requirements to be certified organic. Farmers must prove that their products do not use GMO's and that their products are protected from being in contact with any prohibited substances farm to table; including GMO's. 

We are one of a small number of companies to be certified Plastic Neutral! This means we account for all plastics used in our packaging, production, and shipping, and remove an equivalent amount of low-value plastics from the environment through our partnership with rePurpose Global.

We discontinued local pickup in March 2022.  This is due to food defense regulations which require strict control over who is on premises when food is being packaged.  Local customers can order products to be shipped from our website to any destination in the United States.

Orders shipped USPS can be shipped to a PO box. Orders shipped by UPS cannot be shipped to a PO box. View shipping policy.

We are aware of the inaccuracies that are sometimes displayed through Google's shopping feature. Please note, we do not have control over the information Google chooses to display. Our products are distributed to retailers nationwide and to the best of our knowledge, Google assembles the information it displays by aggregating product listings from multiple sellers. Unfortunately, not all retailers display accurate product information. We recommend visiting our website Great Eastern Sun for the most accurate product information, sales and promotions.