I guess I shouldn't say "good stuff", but rather the concentrated part of the brew that keeps out any bitterness. As you well know I'm sure, the first 30% of the brew is the strongest with the most solubles. Closer to the end of the brew cycle, you're adding slight bitterness to the batch. Anyway, I didn't infuse the batch with coffee, I added orange peel. It turned out not good. Very bland and had some taste of cardboard. I believe this was due to the fact my inexperienced friend who helped out was vigorously stirring the hot wort to cool it faster, which is a definite negative in the brewing process. I gave the whole batch to him.