Origins & Information - (A-Z) Wasabi

Whether or not you expect it, wasabi packs a powerful punch but guess what? Here's another punch for you - the wasabi paste that you've been having with your sushi or covering your peas as snacks probably doesn't have real wasabi in it or if it does, contains little and is low quality (called "western wasabi" by the Japanese, or seiyō wasabi)! Wasabi is actually quite expensive even in Japan due to how difficult cultivating it is ($70-$100 per pound for a plant that takes about 2 years to grow), so the paste that is generally offered in the United States is often a mixture of Chinese mustard, horseradish, soy sauce, and green food coloring. There has been success in farmers in the Pacific Northwest in growing wasabi but in general, the products you'll find on the shelves or on your sushi plate will be imitation wasabi.

So what is it exactly? Wasabi (wasabia Japonica or Eutrema wasabi) is a cruciferous vegetable from the Brassicaceae family (cabbage, mustard, horseradish, etc) that is difficult to grow because it requires a constant stream of cool water, appropriate shade, a specific mixture of soil nutrients, and mild climate. Though the leaves produce the same hot flavor as what we're accustomed to, it is the rhizome (above-ground root stem) that is used as a side dish. Because the flavor is lost in as quick as 15 minutes after the root is cut up, the actual grating of the root is done briefly before needed. It can be sliced or grated (after grating, round up into a ball and let sit for a few minutes for heat to build); if grated, the preferred tool is sharkskin but if unavailable, a small fine grater can be used. It should be eaten in these forms. Any other form such as pastes is not genuine and have already lost much of their volatile flavors. When eaten in its actual form, the initial heat wears off quickly and gives way to a sweet vegetal flavor. As for the paste in the United States, the heat stays for quite a bit and can be powerful even if you've only had a small dab of it!

The interesting thing that you learn about wasabi when you have some whether real or imitation is that you feel the heat in your nasal passages rather than on your tongue. This shocking effect has led to developers attempting to make smoke alarms for the deaf which release wasabi vapors to wake them up in the event of fires at night. However, despite many people's beliefs that it is a decongestant, there has been research that it may actually do the opposite because it flares up blood vessels in the nose. Other health benefits include its abundance of isothiocyanates (chemicals which are significant in the fight against cancer), anti-inflammatory properties, inhibition of platelet aggregation to prevent clot formations particularly in strokes and heart attacks, and anti-bacterial antimicrobial properties (probably why it is typically served with raw fish).

This post is part of an A-Z series I am running for my blog category "Origins and Information" while I am in Vietnam with my family for July. Many of the posts in the series answer questions that were posed by friends/readers. If y'all enjoy the series, I will gladly run another in the future!