Lets say you could only get down 16 oz. If you drank from the full quart already mixed, there would just be less of it but the right concentration. On the other hand if you drank the superconcentrated cup and then only one additional cup, you would have something twice as strong as it should be. Who knows how that would react in the body. That's all. Still, I wouldn't want a superconcentrated salt solution in me, even if it were for a short period whle drinking the rest of the water. Personal preference. Besides, wouldn't that superconcentrated cup be really disgusting? I guess that's the motivation to get the rest of the water down, quick.