chinese v. japanese soy sauce, etc.
Leaving aside the iterations of soy sauce (mushroom, dark, light, etc.), what's the difference between Japanese and Chinese basic soy sauce? Is there any significant difference or are they basically interchangeable, allowing for different brand qualities?
I've noticed that Chinese soy sauces are saltier than the Japanese soy sauces. Also, Japanese soy sauces seems maltier.
With that said, I use the two styles interchangibly for sautes/stir fry, especially when priced the same.
When used as a dipping sauce, some people can tell the difference between Japanese and Chinese soy sauces. I don't use soy sauce in that way so I can't answer that part. Both styles taste like licking salt licks.
<Leaving aside the iterations of soy sauce>
There are numerous Chinese soy sauces and numerous Japanese soy sauces. So when you asked for differences, it depends which ones we are talking.
Southern Chinese light soy sauce is closer to Japanese Tamari in my opinion, but again keep in mind that there are many different types soy sauces from both countries.
Typically speaking, I find Japanese shoyu a touch sweeter than Chinese soy sauce, and often Japanese shoyu has a touch of alcoholic taste to them.
<are they basically interchangeable>
It completely depends your criteria. Think of them like different beers. They are different enough that I can taste the difference, but they are not so different that you cannot use them.