Here’s a great starter blend for a sweeter, cleaner espresso. The absence of North African or Yemeni coffee takes out a little bite from the cup and possibly some lurking fruity ferment flavor. This is, as noted above, a sweet blend used at a street level roasterie/caffe in Rome. They use a Guatemala Antigua for the Central:

  • 50% Brazil Dry-process
  • 25% Colombian Wet-process
  • 25% Guatemala or other brighter Central American

Colombians really don’t pull their weight in a blend (though many people use them as a base or part of their blends), and like using some Sumatra better:

  • 50% Brazil Dry-process
  • 25% Guatemala or other bright Central American
  • 25% Sumatra -Premium like Triple-Pick, Lintong …,

Some sharp sweetness (Central American) hides behind the nutty Brazil flavors and the wonderful Yemeni aromatics. Mandheling adds body and depth. Yemeni coffees are fun for espresso blends, where they can be used like spice to give zest to aromatically or enzymatically flat blends. Roast to Agtron 40 to 35. Good crema production from this blend due to the many dry-processed coffees

  • 40% Brazil Dry-process
  • 20% Panama or other bright Central American
  • 20% Yemen
  • 20% Sumatra Mandheling

Ah, too sweet, too boring. You want something more aggressive, chocolatey? Drop the Centrals:

  • 50% Brazil Dry-process
  • 25% Ethiopian Sidamo or Yemen
  • 25% Sumatra Mandheling Dry-Process

You can certainly keep going along this route by adding other coffees (monsooned, aged, robusta) to discover what they add and what they subtract from the blend.
For an potent Indian Monsooned-type blend you could do something like this:

  • 60% Indian Monsooned Malabar -this high percentage will cup very musty
  • 20% High Quality Robusta: Wet-processed Indonesian or Indian
  • 20% Wet-processed Arabica, for aroma and balance: perhaps Indian, Timor, Java or Sulawesi.

For an potent Aged coffee blend you could do something like this:

  • 40% Aged Sumatra
  • 30% Sumatra, or Sulawesi
  • 30% Guatemala or other bright Central American for aroma and balance