Does Wasabi Go Bad?

You decided to test out wasabi paste. Maybe you needed it for homemade sushi, or add some to a steak, salad dressing, or even mashed potatoes. The paste is spicy and delicious, but you only can use so much at a time. And sooner or later, you start to wonder: does wasabi paste go bad?

Or maybe you decided to give powdered wasabi a try. Instead of buying paste, you went with buying the powder and making fresh paste whenever you need some. But as months go by, you realize that powder is going to be around for at least a couple of years. And that brings up the question of how long does powdered wasabi last?

If any of these questions sound familiar, the rest of the article is for you. In it, we go through storage, shelf life, and going bad of wasabi, both paste and powder. I intentionally don’t cover fresh wasabi, as hardly anyone has access to it.

Sushi and wasabi
Image used under Creative Commons from Franck Mahon

Before we go through all the information, you should know that this article is mainly about the wasabi available in your local grocer. And in almost all cases it’s not “real” wasabi made from the wasabi plant, but a paste made from horseradish and some food dye. The “real” thing is quite expensive, and the demand for it is so high in Japan, that even there stores often sell the substitute. If you’d like to read a bit more about this phenomenon, here’s a short and fun article on the Huffington Post.

How To Store Wasabi

Let’s start with the wasabi paste. The wasabi paste is made of horseradish, mustard, starch, and green food coloring. Sometimes spinach powder is added in place of food dyes. So it won’t come as a surprise that storage recommendations are somewhat similar to horseradish sauce or mustard.

An unopened jar of wasabi should sit in a cool and dark place, away from sources of heat and sunlight. A dark cupboard in the pantry is the best choice, but one in the kitchen will do too. Just make sure it’s not near the stove.

Once you open the jar or container, you need to refrigerate it. Obviously, keeping it always tightly sealed is super important too. If you expect to have the container around for more than a few months, storing it upside down will give you some bonus points. This way fresh oxygen won’t get into the jar, keeping it fresh for a bit longer. And as usual with condiments, always use clean utensils when scooping the paste. This way you minimize the chance of microbial contamination.

Now let’s talk a bit about powdered wasabi. This, usually, is the real “wasabi”, made from Wasabia japonica. Storing it isn’t much different from storing other powders. The powder usually comes in a jar or a tin can, both easily resealable. If your package isn’t resealable, transfer the powder to a small jar or an airtight container upon opening. Like all other powdered spices, keep it closed tightly and away from moisture in a dark and cool cupboard. The kitchen is probably where you want to store it, so it’s on hand when you need it.

Wasabi paste on a plate
Image used under Creative Commons from chispita_666

How Long Does Wasabi Last

Once again, let’s start with the wasabi paste. Like mayonnaise and other condiments, it usually comes with a best-by date. Obviously, that date isn’t an expiration date, but only an estimate for how long the past will retain freshness. That means it should easily keep for at least a few weeks, if not a few months past that date.

Once you open the jar or container, you should try to finish the whole thing within a month or two for best quality. But that doesn’t mean that it’ll spoil or become unpalatable after those two months pass. The quality of the paste degrades gradually, so the sooner you finish it after opening the container, the better. But if you finish it within like half a year, or even longer, it should still be quite tasty (and hot). Past the half-year mark, I’d suggest you check the quality of the leftover paste each time before you use it, just to make sure it’s still okay.

When it comes to wasabi powder, it should come with a best-by date too. But since it’s a spice in powdered form, it pretty much never goes bad in a way that it’s unsafe to eat. Like other spices, its flavor and potency diminish over time. Thus if you store it for a couple of years already, you might need to add more of it to get the usual kick. To check its potency, rub some powder between your fingers, then taste and smell it. If there’s hardly any flavor there, get rid of it. And don’t forget to wash your hands thoroughly after doing that test.

Pantry Fridge
Wasabi paste (unopened) Best-by + 3 months
Wasabi paste (opened) 3 – 4 months
Powdered wasabi (unopened or opened) Best-by + 6 – 12 months

Please note that the estimates above are for best quality.

How to Tell if Wasabi Is Bad?

When it comes to wasabi paste, start by checking the surface for discolorations or any bluish or grayish specks. If there are any, discard the paste. A sniff test is the second thing you should do. If it smells off, throw it out.

Given that the paste looks and smells fine, give a small amount a taste. Decide if it’s good enough for usage based on its quality. If it is pretty bad or you find the flavor lacking, get rid of it. Same thing if it already sits in the fridge for more than a few months.

As I already mentioned, powdered wasabi stays safe to eat indefinitely. Unless, of course, water gets to the package. If there are any signs of mold or the powder is one big clump, discard it. If the powder looks like, well, powder, it’s probably perfectly same to use. Use the process I outlined in the previous section to get a feel if it still has enough heat to use in your dishes.