A guide to roast level

Coffee roast-level is one of the primary qualities that people think of when they think of coffee. Although the darkness of a roast is relatively straightforward, there is a little more going on when it comes to what you are actually tasting.

The Cooking Analogy

Think about heating sugar. If you put sugar in a pan and slowly heat it, it’s going to change from plain sugar to a syrup, then start to change color and turn to caramel i.e. caramelization. If you kept going the taste and color will deepen and eventually start to burn, turning to carbon. The same thing happens chemically in coffee beans as they are roasted since they also contain sugar.

So the basic part of roast-level is just about how hot the beans get during roasting and for how long. If you heat coffee to 420°F/215°C you will have a light roast. At around 430°F/221°C you have a medium roast. At around 460F/238C you hit dark roasts and much beyond that carbon and fire. Experienced roasters can even estimate the final roast temperature by bean color just like a skilled candy maker can tell you how hot cooked sugar was by its appearance.

Why it’s not that simple

Green, unroasted coffee beans, contain literally hundreds of chemical compounds in addition to sugar. Roasting it so that favorable flavors, in the right balance emerge while avoiding unpleasant ones is the art and craft of coffee roasting.

Without getting crazy about the chemistry, there are some reactions that occur in the middle of the roast which can actually produce roasty tastes which has nothing to do with final temperature.

An example. The Pre-Test 1 coffee was roasted 4 different ways (roasting profiles). Although they all had the same end temperature, 425°F, some tasted like they were deeper roasts than others.

If you are interested here is some light reading: Maillard, reactionStrecker synthesisCaramelization (to do: find coffee specific references)

Roast Terminology

French, dark, full-City+, burnt? What? Marketing terminology.

Roast level is a matter of taste and if it makes you happy, then it is good. That said, how do you know what you are buying based on the label? Unfortunately, you can’t really be sure since while there are some formal definitions, they are not followed consistently. Each roaster has their own sense of what light, medium and dark are and generally they will be consistent with the coffee that they roast. Trying to compare between roasters/brands often does not work too well.

So to help here is your not very concise cheat sheet to roast levels from light to dark that you can take with a grain of salt.

Light roasts

  • Some use the term cinnamon roast, which indicates a very light roast.
  • City
  • Beans will look dry. Colors range from light brown to medium brown
  • Taste: Can be bright and acidic tasting. Can be vegetal, floral, fruity but roasty flavors are possible
  • Some roaster’s “light” is another’s medium, which can be confusing
  • Closer to first crack than second crack

Medium roasts

  • Also known as City+
  • Beans will look dry and medium brown
  • Taste: Can be acidic and can have some mild roasty flavors but this roast highlights the coffee’s natural flavors – chocolates, sugars, fruits, florals, spices and you name it
  • A very popular roast level among west-coast roasters
  • Mid-way between first and second crack

Dark roast

  • Also known as Full City or Full City+
  • Beans may be slightly oily and medium to dark brown
  • This is about as dark a roast as you can go while still retaining taste characteristics of the coffee.
  • Just at or slightly beyond second crack

French roast. Italian roast.

  • Beans are oily and very dark brown or black
  • Taste is mainly roasty flavors without much of the coffee’s natural taste left
  • Beyond second check heading toward ignition
  • I am not sure the French or Italians were consulted on the naming