Recently I’ve been putting a japanese seven spice infused oil in my うどん, transliterated consistently as “togarashi” (唐辛子), which I can highly recommend… very tasty stuff. It even has a cute wee push button for dispensing the oil.
I am however somewhat vexed by it! Every resource I can find tells me that this is とがらし, yet every product label I find says とからし. Which is it then, “togarashi” or “tokarashi”?
All references I can find to とうからし (note the う is in there) are with regard to this S&B brand. It seems like it’s just how they call their product.
You are correct that the typical spelling of the plant, and products made from it, is usually とうがらし.
Note that からし on its own is a word, and in the word とうがらし, it’s being rendaku’d with 唐 (meaning Chinese) first. So it’s possible they are just playing with that in the naming of their product.
I think when people say とうがらし they usually mean the chili flakes rather than the chili oil (ラー油). Yes, ラー油 contains とうがらし but it’s not usually called that. Or am I wrong?