What is Wasabi?
Wasabi is usually sold in one of three states. Fresh wasabi is a rhizome (an underground root) or a stem. This can sometimes be bought in international supermarkets or specific Japanese specialty stores. This stem or rhizome is grated to use as a condiment — this is really similar to the process for using fresh horseradish, which is probably one of the reasons the two are so often compared.
You can buy wasabi paste in most supermarkets and that’s what you get with sushi. The paste is made from horseradish, mustard starch and either green food coloring or spinach extract. This is the most common form of wasabi, and it’s what I’ll mainly discuss in this article.
Finally, you can get powdered wasabi. This is actually ade from wasabi roots or stem. It usually comes in a resealable tin and can be stored like a spice. Wasabi powder is the kind of wasabi used on wasabi peas, soybeans, or nuts. Wasabi powder is mixed with water to make an alternative wasabi paste.
Does Wasabi go Bad?
As with most spices and with condiments that aren’t dairy or eggs based, wasabi loses its flavor over time. It is unlikely to flat out go bad unless you leave it well over a year or store it poorly. Instead, it will get less spicy and maybe change texture. This is true of both wasabi paste and powdered wasabi, but they have different storage needs and shelf lives.
Wasabi, both powder and paste, will usually have a best-by date. This isn’t a date past which it’ll be dangerous to eat the wasabi, rather the last date the manufacturer thinks the wasabi will be at its best. If you store your wasabi well though, your wasabi might still be good quality for months past the best-by date.
How to Store Wasabi
Wasabi paste and powder have different storage needs. Let’s start with paste.
An unopened jar of wasabi paste can be stored in the pantry, as long as your pantry is cool, dry and dark that is. Heat and light will both negatively affect the flavor of the paste and cause your wasabi to go bad faster.
Once wasabi is opened it should be kept in the fridge. Always keep the lid tightly sealed after you initially open it. To make sure the seal stays good you should wipe the inside of the lid and the outside of the wasabi jar pretty regularly. Dried paste could stop the lid closing properly and let in both air and moisture, plus the wasabi on the outside could go bad and contaminate the rest.
Keep powdered wasabi in a cool, dark place. The more genuinely cool and dark, the longer it will last! If it didn’t come in a resealable package then pour your wasabi powder into a glass jar with a good lid and keep the lid tightly closed when you aren’t using the powder. When cooking with wasabi, keep your open jar away from moisture as it will absorb ambient moisture and steam.
As with all condiments and spices, you should use clean, dry utensils every time you go into the jar or tin to get some wasabi. Any detritus on a used spoon (for example) could contaminate the wasabi and cause it to go bad, and water could ruin powdered wasabi in particular.
Can You Freeze Wasabi?
Wasabi isn’t a prime candidate for keeping in the freezer. You can freeze fresh-grated wasabi if you flash freeze it immediately after grating and then seal it in freezer bags. Paste, though, will change consistency and lose fire in the freezer. Plus wasabi lasts ages in the fridge, so why risk ruining it?
If you still want to freeze wasabi then you can simply put a partially used jar into the freezer as it is. A full jar, however, runs the risk of exploding. If you have a full jar then decant it into a slightly larger but still airtight container to freeze.
When you take the wasabi out you will need to defrost it. Do this at room temperature, stirring it from time to time once it’s soft enough.
How Long Does Wasabi Last
Wasabi is a really long-lasting condiment. Both the powder and the paste easily keep for months or longer if stored properly. As ever, this is an inexact science so you should test your wasabi from time to time to check how it’s holding up. It’s unlikely to taste bad, but may begin losing flavor after more than 6 months.
Here are the ballpark figures. Wasabi paste will last for up to 6 months past its best-by date if it has been opened and kept in the fridge. It will last a year past best-by if it hasn’t been opened.
Wasabi powder will last up to 12 months past its best-by even if it has been opened as long as you store it carefully.
How to Tell When Wasabi is Bad
It’s not always easy to tell when wasabi is past best, and it’s unlikely to go noticeably bad. If wasabi has been contaminated, however, by any other food getting into the package of powder or paste, then it may begin to show patches of mold. If this happens, throw it out. Likewise, if the paste smells vinegary or strangely ripe then chuck it.
If wasabi paste looks okay then give it a taste. If it’s not longer spicy or tastes at all strange, again it could be vinegary, then get rid of it. Unless it’s actually on the turn and going vinegary or fizzy, it’s your choice what you consider bad with wasabi. A small loss of flavor may be totally fine — you’ll just need to lose a little more!
Powdered wasabi should remain safe to eat pretty much indefinitely. The one exception to this is if water has gotten into the package, whether through spillage or just absorption from the air. If it’s got wet, wasabi powder will begin to clump and could show signs of mold.
If the powder looks okay, give it a sniff and see if it still smells like wasabi. You can also dip a clean, dry finger in and taste a very small bit of powder. Be careful though, if it’s still good it might blow your head off!]]>