General Principles of Home Roasting:

There are countless ways to roast coffee, from skillets over open fire, to traditional ovens (see oven roasting for details), to popcorn poppers, to woks, to BBQ’s. Despite the myriad of different roasting techniques that exist, they all share common fundamentals of coffee roasting. Incidentally, we feel that the commercially manufactured home coffee roasters produce the most consistent, flavour enhancing roasts for the home roaster. These machines take away some of the guess work, produce nice even roasts, allow you to sit back and observe or be as technical and involved as you care to be and in general make home roasting fun and easy ( see our home roasters form more information). Home roasting really is all about learning to recognize the stages of the roasting process and to learn to use all of your senses. Sight, sound and smell will be used to evaluate the roast and guide you through the steps of roasting your own coffee. One worthwhile tip is to use a log or journal to keep track of your roasts. You should keep track of coffee origin, weight used, roasting profile/time used, along with time to first/second crack etc. Having a detailed record of these variables will allow you to modify future roasts and hone your roasting skills.

A note on safety: coffee roasting starts out very slowly and as the coffee loses moisture the beans will gradually yellow. The later stages of the roast will progress very rapidly and it is possible to over roast or even burn the coffee and damage the roaster. So never leave your roaster unattended and follow all of the manufactures advice on safely operating the home roaster.

General Roasting Observations:

• The length of time, as well as temperature of the roast, are crucial in producing a quality cup of coffee. Typically, coffee is roasted for about 10 to 20 minutes at temperatures ranging fro 400 degrees F to 425 degrees F.
• After the first few minutes of the roast, the green beans will start to yellow as they lose moisture. A slightly grassy smell will be emitted.
• A few minutes later, as more moisture dissipates and the beans have taken on a light brown colour, the first audible cue should be heard – the “first crack”.
• During first crack the chemical make-up of the coffee bean has changed: sugars have started to caramelize, trapped steam cracks open the beans and vents, oils which give coffee much of its aroma and flavour begin to migrate to the surface of the beans. The coffee is considered roasted from this point on and the degree of roast obtained is up to you. The longer the coffee is roasted, the darker the roast. It’s a matter of personal taste preference from this point and what type of flavours you want to highlight.
• Lightly roasted coffee will have a sharp, more acidic taste than darker roasts. Since the coffee is exposed to less of the flavour altering properties of heat, the coffee maintains the bean’s nuances or unique characteristics found in higher quality beans. Don’t roast high quality beans too dark because you will lose much of the bean’s unique natural flavour.
• Darker roasted coffee will have less acidity, less caffeine but due to the prevalence of oils on the bean surface, will have a shorter shelf life. Darker roasts tend to highlight the smoky, slightly burnt taste of the roasting process rather than the natural flavour contained within the bean. If you want a stronger cup of coffee try altering the quantity of a lighter roast coffee or the amount of water used in brewing rather than roasting too dark. This will ensure a stronger cup with great flavour profile.
• As the roast continues past first crack, caramelization continues, more oil migrates to the surface and the beans expand as the roast darkens. Often times the beans will double in size during the roasting process.
• The next audible cue is the “second crack”: the cracking noise in the roast when the cellulose matrix of the beans begins to break down. It can be quite impressive with small fragments of the beans being blown away but can be more difficult to hear than first crack. The beans will be a deeper brown colour, with some showing signs of oil on the surface.
• From this point the coffee will become very dark and pungent smoke is produced as the oils begin to burn. Too much further past this point and you have burnt coffee - so watch out!

Common Roast Levels: