Along with soy sauce, wasabi is well known to Americans due to the popularity of sushi. Wasabi can come in 3 different forms; a real fresh root, powder type, and tube type.
Freshly ground root is fragrant with a touch of sweetness in the spiciness. But one root costs around $8 in Japan and it’s not a common item to keep around at a regular Japanese household.
Tubed wasabi most common, as it is an affordable substitution. It’s sold in the United States as well. Some tubes contain prepared powder wasabi only, but others contain the mixture of western horseradish and a small amount of real wasabi.
It is rare to see a 100% real ground root in a tube. This is due to the cost and availability. Also, because horseradish is much spicier than Japanese wasabi, makers add more horseradish to meet people’s demand for spicy food.
Tubed Wasabi made of powder is smooth, but the one with real root contains dark speckles. Wasabi powder is also sold in the market. Green powder is mixed with a small amount of water to form paste. This doesn’t contain any real root at all.
Because powdered wasabi is the most cost effective, cheap sushi restaurants and ready made sushi are using this type.
Wasabi tubes are sold at Japanese grocery stores, Korean grocery stores, and Chinese grocery stores. For those who wish to buy online, here are the links;