Here's my newest (and best - so far) blend for espresso shots:
(Measured by volume, before roasting. "1 part" is 4 oz (1/2 cup - volume!).
Roasted separately, except for the last two, which were blended green and
then roasted. The Brazil was roasted in two batches.)
2 parts Brazil Serra Negra - roasted fairly dark (2nd crack + 2.5 minutes)
1 part Guatemala Huehuetenango Catinil - dark (2nd crack + 0.5 minues)
1 part Sumatra Mandheling Special Triple Pick - dark (just into 2nd crack)
0.5 parts Papua New Guinea Purosa and
0.5 parts Indian Kaapi Royale Robusta - fairly dark (2nd crack + 1 minute)
Silvia Espresso Machine, 22-25 sec shots, double shot filter
Even though I didn't wait more than 3 hours after roasting before I made
the espresso shots, I got unbelievably good results. Abundant crema (dark
reddish brown), perhaps not the most crema I ever got, but up there with
the best. Sensational smoothness in the chocolate notes, a bit of almond,
and a touch of floral and fruitiness. No bitterness or high acidity; nice
high body, excellent mouth feel.
I really like this blend a lot. It emphasizes all the dimensions I like,
and it minimizes the ones I don't.
Feel free to comment and offer suggestions for improvement!