You decided to try the wasabi paste. Maybe you needed it to make homemade sushi, or add a little to a steak, salad dressing, or even mashed potatoes. The paste is spicy and delicious, but you can only use a limited amount at a time. And sooner or later, you start to wonder: does wasabi paste go bad?

Or maybe you decided to try wasabi powder. Instead of buying pasta, you have opted to buy the powder and make fresh pasta whenever you need some. But as the months go by, you realize you won’t be using it for the next year or so. And that leads us to wonder how long wasabi powder lasts.

If any of these questions sound familiar to you, the rest of the article is for you. In it we review the storage, expiration and deterioration of wasabi, both in paste and powder. I’m intentionally not talking about fresh wasabi, since hardly anyone has access to it.

But before we jump into all the information, you should know that this article is mainly about the wasabi available at your local grocery store. And in almost all cases it’s not “real” wasabi made from the wasabi plant, but rather a paste made with horseradish and some food coloring.

The “real” one is quite expensive, and its demand is so high in Japan, that even stores there usually sell the substitute. If you want to read a little more about this phenomenon, here is a short and funny article in the Huffington Post.

How to preserve wasabi

Let’s start with the wasabi paste. Wasabi paste is made from horseradish, mustard, starch, and green food coloring. Powdered spinach is sometimes added instead of food coloring. So it won’t surprise you that the storage recommendations are somewhat similar to those for horseradish sauce or mustard.

An unopened jar of wasabi should sit in a cool, dark place, away from heat and direct sunlight. A dark pantry cabinet is best, but one in the kitchen will also work. Make sure it’s not near the stove.

Once the jar or container is opened, you must refrigerate it. It is also important to always keep it tightly closed.

As with all seasonings, always use clean utensils when picking up. This will minimize the possibility of microbial contamination.

Now let’s talk a little about wasabi powder. Wasabi powder is usually real “wasabi”, made from Wasabia japonica. Storing it is not much different from storing other powders.

The powder usually comes in a jar or a can, both of which are easily resealable. If your container is not resealable, transfer the powder to a small jar or airtight container immediately after opening.

Like all other powdered spices, store it tightly closed and away from moisture in a cool, dark cabinet. It is probably in the kitchen where you want to keep it, to have it at hand when you need it.

How long does wasabi last?

Once again, let’s start with the wasabi paste. Like mayonnaise and other condiments, it often comes with an expiration date. That date is not an expiration date, just an estimate of how long it will keep fresh. That means it should easily keep for at least a few weeks, if not a couple of months after that date.

Once the jar or container is opened, you should try to finish it all in a month or two for the best quality. But that does not mean that it will spoil or become tasteless once those two months have passed.

The quality of the paste gradually degrades, so the sooner you finish it after opening the container, the better. But if you finish it within half a year, or even longer, it should still be quite tasty (and hot). After half a year, I advise you to check the quality of the leftover paste every time before using it to make sure it is still good.

As for the wasabi powder, it should also have an expiration date. But because it’s a powdered spice, it hardly ever goes bad in a way that’s unsafe to eat.

Like other spices, its flavor and potency diminish over time. So if you keep it for a couple of years, you may need to add more to get the usual flavor.

To test its potency, rub some of the powder between your fingers, then taste and smell it. If it barely has any flavor, get rid of it. And don’t forget to wash your hands well after doing that test.

Please note that the above estimates refer to the best quality.

How do you know if wasabi is bad?

When it comes to wasabi paste, start by checking to see if the surface is discolored or has bluish or grayish spots. If there is any, discard it. The second thing to do is a sniff test. If it smells bad, throw it away.

If the paste looks and smells good, try a small amount. If it’s bad enough or seems lacking in flavor, get rid of it. The same if it remains in the refrigerator for more than a few months.

Like I said, wasabi powder can be eaten indefinitely. Unless, of course, water gets into the container. If there are signs of mold or the dust is a big lump, throw it away. If the powder looks like, well, powder, it’s probably perfectly usable.