Most grocery store wasabi is not made from real wasabi, but rather from a mixture of horseradish, mustard, and food colouring. Real wasabi, which comes from the grated root of the Wasabia japonica plant, is difficult to cultivate and quite expensive.

The taste of real wasabi is often described as being more complex and nuanced than the flavour of imitation wasabi found in most grocery stores. It has a distinctive, refreshing heat that dissipates quickly and leaves behind a sweet, vegetal flavour.

In contrast, the imitation wasabi found in grocery stores tends to be much stronger and more pungent, with a sharper, longer-lasting heat that can overpower other flavours. Additionally, the artificial colour added to the imitation wasabi often makes it appear brighter and more fluorescent than real wasabi.

Overall, the taste of grocery store wasabi is quite different from that of real wasabi, and it may not be a good substitute for those looking to experience the authentic flavour of this prized Japanese condiment.