my attempt at pulling shots with a light roast Malawi coffee

There are some day when all of your shot making comes out great, the quality of the espresso are great and there are days where you just try everything but a great shot just ellude you. Yesterday was that day for me. I have had great success with pulling espresso shot with Malawi coffee before; the Malawi that I had is a high quality washed coffee in the green form. With previous roasting sessions,  I have been roasting this into the FC or FC+ range ( dark to very dark, but no vissible oil, only first few snaps of second crack) and It had been producing absolutely delicious espresso shot; it is not nutty but very fruity and lively with light cocoa taste. 

This time, I was thinking of roasting it a bit lighter, may be C+ so that I can get more fuitiness out of it and also for brewing in the french press. I waited for it to rest for about three days before starting to pull shots with it; and that was yesterday. First shot of the day was a bit too fast, pulled into a cappuccino cup and with microfoamed milk add to "save" the apparently fast shot. The cappuccino was unexpectedly delicious. I next proceed to grind finer with the Vario, in goes fourteen grams of Malawi ground into the basket of Ponte Vecchio. The resulting shot was slow, wattery and no creama; surely I think I must have screw up with the basket preparation (a very rare occurance as I'm very meticulous). Next shot in, the same grams of coffee, the same grind setting, same Ponte Vecchio flush routine, but the same nasty wattery sour result!

I droped the dose to thirteen grams, grinding a bit courser but the espresso never reach the zenith, the creama is alway pale and thin with no speckling, the mark of excellent espresso. After pulling may be 6-7 of these shots, I have come to the conclusion that this roast is probably only good for drip type of brewings or for a decent americano. Next time, if I ever want to put these been through my espresso machine,  I must roast these much darker.