Home Coffee Roasting

There’s a moment in every roast when the beans start to crackle and the room fills with the smell of coffee becoming itself. Roasting at home turns green beans into a cup that’s entirely yours: the origin you chose, roasted the way you like it, at its freshest.

Since 1978, our family has shared its passion for coffee, along with our know-how. This guide brings together what we’ve learned about how home coffee roasting works, choosing the right roaster, and finding green coffees worth exploring.

Holiday flatlay with a warm cup of Terra limited-edition Christmas tea, candy canes, evergreen and winter gifts, evoking soft seasonal warmth.

This holiday season, buy a Gene Café CBR-101 or CBR-301 by December 31 and save on our green coffees for up to six months. Each offer is explained below, along with how long it lasts.

Gene Café CBR-101

A straightforward roaster for learning the craft. You set the temperature and time, watch the beans through the glass chamber, and let the automatic cooling cycle finish the roast.

With your CBR-101, enjoy 15% off our green coffees for three months.

Discover the CBR-101 →

Gene Café CBR-301

Bluetooth roast profiling lets you save the roasts you love and repeat them, batch after batch. It’s made for the home roaster who wants to refine every variable.

With your CBR-301, enjoy 15% off our green coffees for six months.

Discover the CBR-301 →

Freshly roasted coffee beans at Terra's Montréal roasting facility.

Why Roast at Home

Roasted coffee is at its best within a few weeks of roasting, and green coffee keeps far longer. Roasting at home lets you keep a supply of green beans on hand and roast small batches as you need them, so every cup is fresh.

It also opens up a level of control that buying roasted coffee can’t offer. You choose the origin, the processing method and the roast level, then taste how each decision shapes the cup. A single coffee can taste bright and floral at a light roast, then rich and chocolatey a few minutes later. Discovering that range for yourself is much of the pleasure.

How Home Roasting Works

Every roast moves through a few recognizable stages. In the first minutes, the beans dry out and turn from green to pale yellow, with a grassy, bread-like aroma. As they heat further, they brown steadily while sugars and amino acids develop the compounds that give coffee its flavour and colour.

The most important milestone is first crack, an audible popping as moisture and gases escape and the beans expand. Light roasts finish shortly after first crack begins; medium roasts continue for a minute or two beyond it. Darker roasts approach second crack, a quieter, faster crackle, where oils begin to surface and roast character takes over from origin character.

Once you reach your target, the beans must cool quickly to stop roasting. Throughout the process, the beans shed a papery skin called chaff, which your roaster collects for easy removal.

Choosing a Home Roaster

Both Gene Café roasters use the same core design: hot air circulates through a glass chamber that rotates off-axis, so the beans tumble continuously and roast evenly without touching a heating element. Each roasts batches of up to 300 g of green coffee, and both finish with an automatic cooling cycle.

Gene Café CBR-101

The Gene Café CBR-101 keeps things simple. You set the temperature, between 190 and 250 °C, and the roast time, then adjust as you watch and listen. You can also start the cooling cycle at any moment to end the roast exactly where you want it. A full city roast takes about 15 minutes plus cooling, which makes it a practical machine for learning to read a roast by sight, sound and aroma.

Gene Café CBR-301

The Gene Café CBR-301 adds Bluetooth connectivity and a companion app, so you can save roast profiles and recall them across sessions. Dial controls and a digital display show temperature and time together, and a drawer-style chaff collector simplifies cleanup between batches.

If you want to learn roasting hands-on and keep the process simple, the CBR-101 is a natural place to start. If you plan to compare origins closely or repeat favourite roasts exactly, the CBR-301’s saved profiles will repay the investment.

Hands holding unroasted green coffee beans used for making coffee extract

Choosing Green Coffee

Green coffee is the raw seed of the coffee cherry, and its origin and processing shape everything a roast can bring out. Washed coffees tend to roast predictably and taste clean and bright. Natural and pulped natural coffees, dried with some or all of the fruit, bring more body, sweetness and fruit character.

For your first roasts, choose a coffee that’s forgiving across roast levels. Brazil Bela Vista Pulped Natural and Colombia Supremo Origen SCR 17 are both reliable for learning your roaster’s temperature and timing. Once you’re comfortable, varietals such as Colombia Pink Bourbon reward closer attention at lighter roast levels.

Each coffee in our green coffee collection includes its origin, processing method, cupping profile and roast guidance to help you plan a roast.

Cooling, Resting and Storage

Both Gene Café roasters cool the beans automatically once the roast ends. For faster cooling, the Gene Café CBC-101 coffee cooler brings freshly roasted beans below 30 °C in about a minute per 400 g, which locks in your chosen roast level more precisely.

Roasting produces smoke, especially at darker roast levels, so roast in a well-ventilated area, ideally under a range hood or outdoors, away from anything flammable. Always roast with the lid secured, never leave the roaster unattended while it runs, keep a fire extinguisher within reach, and check your green coffee for small stones or debris before loading it.

Care and Maintenance

A clean roaster roasts more consistently. Empty the chaff collector after every batch, and clean the chamber and filters regularly, letting all parts dry fully before the next roast.

Roasting produces smoke, especially at darker roast levels, so roast in a well-ventilated area, ideally under a range hood or near an open window. Always roast with the lid secured, never leave the roaster unattended while it runs, and check your green coffee for small stones or debris before loading it.

Frequently asked questions

Yes, some. Light and medium roasts produce relatively little, while darker roasts produce more. Roasting under a range hood or outdoors keeps it manageable.

Both Gene Café roasters handle batches of up to 300 g of green coffee. Since beans lose weight as they roast, a full batch yields a little less roasted coffee, enough for several days of brewing.

Stored in a cool, dry place away from strong odours, green coffee stays in good condition for many months. That makes it practical to keep several origins on hand and roast as you go.

Most coffees are ready for filter brewing after a day or two. For espresso, wait about a week, since resting lets carbon dioxide escape and helps shots extract evenly.