Coffee roastiness is one of the most noticeable qualities 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. The same thing happens in coffee, which also contains sugar.
So the simple part of roast level is just how hot it gets before you end the roast. If you heat coffee to 420°F/215°C you will have a light roast. 430°F/221°C and you have a medium roast and beyond that dark roasts and eventually carbon and fire. Knowledgeable 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.
French, Dark, Full-City+, burnt? What? Marketing and mythology.
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? To help here is your not very concise cheat sheet to roast levels from light to dark.
- Also known as cinnamon or City
- Beans will look dry. Colors range from light brown to medium brown
- Taste: Generally acidic. Can be vegetal, floral, fruity, roasty flavors are possible
- Some roaster’s “light” is other’s medium, which can be confusing
- Closer to first crack than second crack
- 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 you name it
- A very popular roast level among west-coast roasters
- Mid way between first and second crack
- Also know 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