cannonfodder wrote:You need to let the beans rest for about 4 days for espresso.
Agreed, although depending on a myriad of factors, a longer rest period may be beneficial as well. For me and my roaster it seems that a SO Harrar (at FC to FC+) peaks in flavor at 6-7 days and begins to wane thereafter.
I agree with trying your roasts a little "lighter". I've been roasting most of my SO's and blends at FC to FC+ for the past several months now but recently took a batch of my "house blend" (Espresso Blend #27-G ...) well into the second crack. Had lots of bite with tons of smoky chocolate taste. OTHO, this roast level covered up much of the "balance" in the cup for me (e.g. fruit and full body). Frankly, my taste buds didn't care for it, too much "slap" and "punch". So this might be your finding as well-
Keep a roasting/cupping record in a log book and play with these variables (days of rest, roast etc.) to see what works best for you and yours-