Depending on what you read you may have up to five different names for each of these named roasts. This is not intended to be all-inclusive. It will, however, provide you with a widely accepted base of terminology that other roasters will recognize, and still give you enough knowledge to look smart in front of your less evolved friends.
Note: The changes noted below are easily seen in fluid-air bed roasters; if you’re using a drum roaster you need to rely more on sounds and smells.
Roast Recommendations for particular coffees
Green Let’s start at a place we all recognize and everyone can agree. Beyond here, however, things get a little subjective.
Stoke the fire…add the heat…watch the beans start to look and smell like coffee.
Start your roaster and the beans start to move, but that’s about all you can see for awhile. Inside the beans, however, the water is beginning to evaporate and the chemical decomposition of the sugars (pyrolysis) is occurring. The beans get brighter, then turn yellowish and emit a wonderful smell. Don’t stop here unless you like drinking straw or lawn clippings.
As the internal water evaporates the beans expand, causing a cracking sound. This crack is relatively loud and irregular in its cadence. As roasting progresses, this “popping” diminishes. During this same period, the beans will expand to roughly twice their green size and lose approximately 15% of their weight - they begin to “float” in the roasting chamber.
Cinnamon is the first named roast. The beans are light brown and dry. Coffee ground from this roast looks a little reddish, almost like cinnamon. Beans stopped here tend to taste underdeveloped and grassy.
City / American These beans are a darker brown but still dry with a dull (as opposed to shiny) finish. City is as dark as you can get without entering the next major landmark in roasting, which is…
The second pop/crack is more of a soft staccato sound as the beans’ cell walls break down. What appear to be oils start to show up and little flecks of bean pop off. To many, this is the most significant event in the roasting process.
IMPORTANT FLAVOR NOTE: Beans NOT allowed to go to “second crack”, where the sugars begin to carmellize, will tend to taste flat, have somewhat of a grassy taste and a strong aftertaste that some really enjoy, while others dislike it.
Full City / Vienna Full City is where the second pop/crack begins; the beans start to develop some oil on them (while some remain dry) and they are a nice chestnut brown color. This roast style is considered by many to be the ultimate roast: the perfect balance point in terms of acidity / brightness, aroma, body and varietal flavor characteristics (which is what you see on our coffee matrix). Coincidentally, this is the roast style most home roasters end up adopting as their favorite, especially those who initially liked the shiny, dark roasted beans they used to buy in the store.
Espresso “Sheeny” dark brown beans, not quite oily enough to be shiny; some beans may not even have a sheen yet.
Italian to French These are the very dark brown-to-black oily beans that look almost like jelly beans. At this stage, sugars in the beans are carbonizing (a step past carmelizing) so you get a bit of a charcoal taste.
Charcoal This is not really a roast name, but just in case you really mess up a
roast, tell your friends it is a new roast, then quietly give the beans to your kids
or grandchildren along with a sketch pad…or let them use the sidewalk.
“CURING or DE-GASSING YOUR BEANS”
There is such a thing as coffee being TOO fresh !! Going from the roaster right to the brewer (via a grinder of course) will be tasty; however most coffees will taste pretty much the same until their flavors have sufficient resting time to develop.
Beans need to cure for a minimum of FOUR hours…to an ideal time of TWELVE hours (this is my opinion only), and some even TWENTY-FOUR hours or longer in order for the flavors to fully develop. You will find opinions on this subject to vary widely, so, again, find a starting point and determine your own time.
There is, however, a point where resting turns to retirement, where freshness is gone and your beans become stale. Again, there are many opinions on how long coffee is considered fresh; my opinion it is between 7-10 days. The reality is that coffee starts to degrade as soon as it reaches its peak, wherever you determine that to be for your own taste; flavor degradation is enhanced by being exposed to air during curing, so it is best to cure and keep your roasted beans in an airtight container until you are ready to grind and brew it.
Since we have talked about freshness and time I will weigh-in on freshness as it concerns ground coffee: 15 minutes to an hour, after which time it will be noticably “not-fresh” - sounds better than stale.
So, as a matter of practicality, I suggest as a minimum, roasting in the evening, letting your beans cure overnight, then grinding and brewing your first batch the next morning. You do not have to do this every day, but if you run out completely it’s a good idea - remember they will easily stay fresh (enough) for a week or more if they are stored in an airtight container.
I am frequently asked to recommend a particular roast for a particular coffee and I
rarely do so…and for a reason.
There are those who consider home roasting a science
and attempt to quantify and control all the variables to be able to
replicate any given roast at any given time. While this is admirable, it is not for everyone.
There are others who consider coffee roasting as an artform and want to know the basics, so they can develop their
creativity from there. This is my perspective; one in which the perfect roast is the one
that the individual deems to be their perfect roast, not the one I or anyone else says
is the best. I truly consider it as personal a decision as selecting a spouse, and I’m sure you wouldn’t want me or anyone else making that decision for you.
Knowing I come from the artform perspective, here are my thoughts…ironically based on
scientific evidence. Every type of coffee goes through the same chemical changes at the same
places in its roast cycle, as outlined above. Coffees develop (conveert) sugars during the roasting process,
sugars which carmelize, and then carbonize as they are roasted longer.
It is at the point where the majority of those sugars have carmelized, but before they
carbonize, that the flavor characteristics of that coffee have developed; i.e. reached their flavor peak. Peak does not necessarily mean that’s where
they taste the best to you; it does mean their flavors have developed; their subtle nuances and
varietal characteristics are evident. This is the Full City roast style mentioned above, although some refer to it as “city” or “partial full city - whichever you call it,
I recommend you start there!
You may not like those particular flavors and prefer to roast past them,
covering them with more carbonized sugars. Or you may jump for joy at the flavors you
have already uncovered. You may want to accentuate some of the more subtle nuances by roasting a little lighter.
Roasting lighter also has its side-effects, too: your coffee will have a lingering aftertaste with
the lighter roasts. This is neither good nor bad, but will be there for you to evaluate.
In summary, I believe that where you roast any coffee is your call; you are the boss! Now that you know what happens at each step in the process, go for it and have fun. Welcome to the wonderful world of home coffee roasting !!
Here we are at the end of the page; this is where the bottom line resides.
The bottom line is YOUR TASTE AND PREFERENCES ARE ALL THAT MATTER.