Horseradish substitute in creamy chowder I would like to cook a pot of seafood chowder today but it's Christmas, the stores are all closed and I forgot to pick up horseradish. Is there a good substitute for horseradish in a creamy chowder?

I figured wasabi and mustard might work and those ingredients do turn up in a Google search but I'm not sure that they would work in a chowder. The flavor would be fine, I think, but I'm worried that the final product would be tinted green or yellow depending on the substitution. I could see wasabi and especially mustard working well to replace horseradish in something like crab dip though.

Any other ideas?
If the wasabi is pure wasabi powder, it's only a pale yellow color, not neon green like wasabi you get at a sushi restaurant. A lot of wasabi actually has food coloring in it. Similarly mustard powder is bright yellow... but in either case if you only use a bit of powder (which can be quite strong) it might not impart a lot of color on the final dish.

If the soup needs to be spicy you could try ginger. I also see here you could try black radish, which does have a very spicy taste but apparently it requires advance preparation.