Been trying to knock down some brightness and acidity of mostly Centrals and some African for espresso blending. The centrals I'm using have better than average body. I'd like to be able to increase my % of these without it being too bright or acidic. Thinking of trying by adjusting my 1st crack between 9 1/2- 12 1/2 min and 2nd between 17-19 1/2min. stopping some just before 2nd, some 20-30secs in and some a little farther. If I'm stretching after 1st how should I adjust the time from start to 1st, longer, shorter? With a 4-6*/min. bean temp. rise during 1st? These will be used with Brazil and Sumatra(it's good this year). Any suggestions? Generally how long of a stretch should I be trying?
ps I can monitor bean mass and air temp. for control.