You don't need to dilute it. When I watched a local plantsman/propagator make it on a television segment, he put willow pieces in a stock-type pot just covered with water by a couple of inches and simmered (barely) with lid overnight. It was definitely darker than weak tea, looked more like cola.

Thanks. I have so much of it I've got to figure out a way to use it or lose it. A friend suggested that perhaps I could freeze it.

I also read somewhere that ww will stay fresh for a year or longer if you refrigerate it. I wonder if that's true. I'm afraid if I leave it in the fridge, I may someday think it's tea, add sugar, drink it and sprout roots.

When I made it I crushed the willow stems before simmering them. Mine was about the color of weak tea. I didn't bother storing it but I don't see why you couldn't freeze it.