I'm trying to find information on how long to roast coffee from different regions. Do certain origins taste better when roasted to certain levels? Is my question making sense? For example at what roast level would a Yemen Mokha Sana'ani make the best espresso? And I guess another good question is what regions make the best espresso? I'm really in a haze about this whole home roasting thing.

Thanks!

It's mostly a matter of taste, and home roasting is about experimentation. However, there are a few very general guidelines, with lots of exceptions.

-- All coffees can be roasted light. Light roasts, however, may be an acquired taste for those whose coffee taste developed with darker roasts. Light roasts, pulled just after the end of the first crack, are used for evaluating coffees.
-- Low grown arabica from Brazil or the islands should not be roasted beyond a rolling second, since they get ashy.
-- The roasting range for espresso is a little narrower than for other brewing methods. The lightest roast (except in Arabiia, see below) for brewing is end of the first crack, while for espresso, it's just before the first pops of the second. Darkest for brewing is beyond the end of the 2nd crack, for espresso, the darkest is as the 2nd is declining
-- Most people think naturals (dry process) coffees are the backbone of espresso blends, and should constitute at least 50% of any blend.
-- Indonesian coffees are thought particularly suitable for darker roasts. Some also put Guatemalan Antiguas in this category.
-- The classic Western style Yemen roast is slightly into the 2nd crack. The beans roast unevenly, and this level gets the entire range into the drinkable zone. However, on the Arabian peninsula itself, these coffees are roasted about halfway to three quarters through the first crack (leisurely tempo though), and this makes a very fine and delicate brewed cup if done right. I especially recommend trying this at least once with some Ethiopian Sidamos and Yrgacheffes.

Thank you Jim for such an informative post. I'm keeping it for when people ask me the same question. I'm not sure I could have summarized it so well.

Hi Ed, It's kind of sad. After years of home roasting, these are about the only generalizations that have stood up. I suppose when I get your experience, none will be left; and I'll have to stop giving advice

When trying out a new green I roast three batches. I will roast just out of 1st (city), almost to second, possibly the first snap of second (full city) and just into second (full city+) so I can get a sense of the coffees range. Then go from there changing roast speeds (or as much as I can with the HotTop) to see how the flavor develops. Then when I have it all figured out and a nice blend worked up, I run out of something and have to start all over.

In my limited experience, lighter roasts tend to accentuate the fruit and light spice (anise, cinnamon, coriander) notes in a blend while preserving much of its acidity. A medium roast brings out more of the wine notes, dark fruit, raisin, plum and some nuttiness. The dark roasts, start of second to rolling second, will bring out more nut in some beans, charcoal in others, heavier spice such as pepper and most of the chocolate note is developed here. The acidity is muted and the roast flavor is overtaking the origin flavor. There are a few beans that will work well in this range but hitting that sweet spot between chocolate bar and charcoal can be very tricky.