Dark vs. Light Soy Sauce
I made a teriyake marinade but used Premium Dark Soy Sauce (usually I use light soy sauce), will it make much of a difference...good or bad?
i think that contrary to popular belief --light soy sauce (usukuchi) is actually saltier than dark.
Dark soy sauce has molasses in it, so presumably it will be a little sweeter and fuller bodied than light soy sauce. It probably won't be as salty as light soy sauce. Linda Bladholm's "The Asian Grocery Store Demystified" says dark soy sauce is ideal for marinades, so if she's right, you're in business!
Dark soy is used for coloring (e.g. Fried Rice). Light soy is usually saltier. There are many kinds of soy one for fish, one with ponzu, the list goes on. But for beginners its light or dark.
You can always read the ingredients lists and check the nutrition information. That gives a pretty precise picture of saltiness and sweetness for soy - sodium and carbohydrates.
The terminology varies, though. Chinese soy sauces are "thin" (everyday) and "black" (colored with molasses). They are both equally salty.
A Japanese soy called "light" will be lighter in color and saltier than another Japanese soy.
An American soy called "light" will be less salty than another American soy.
And I use them all interchangably, depending on my mood, and adjusting for saltiness by taste. Not very authentic.