Ways to roast coffee

Alongside the beans' natural characteristics, roasting is crucial to coffee's flavour, aroma and perceived strength. What roast levels are there, and how do they change the cup? Does a light or dark roast contain more caffeine? And what is involved in roasting coffee at home?

Before green beans are ready for conventional brewing, they undergo a complex roasting process. This develops the taste and aroma coffee lovers recognise. A particular coffee can be roasted in different ways, but some profiles reveal its character better than others.

A change of a few minutes or a few degrees can alter the result. Comparing different roast levels is therefore a rewarding way to find what you like.

Coffee roast levels

During roasting, the beans change colour, aroma, flavour and density. Green beans do not yet have the familiar character of roasted coffee and can be stored for much longer under suitable conditions.

Roasted beans lose freshness more quickly. Keep them in protective, well-sealed packaging, use them while fresh and grind them shortly before brewing.

Roast descriptions are commonly grouped into three broad categories. The temperatures below are approximate historical reference points, not universal settings: the reading depends on the equipment and where temperature is measured.

Light roasting

At around 200°C in the scale used here, the beans remain light brown and retain pronounced origin character and acidity. This can work well for African coffees, including Kenyan beans with wine-like, refreshing or citrus notes.

• Cinnamon roast — around 196°C: very light, cinnamon-coloured beans, producing a delicate, highly acidic cup that can seem closer to tea than a strongly roast-flavoured coffee.
• New England roast — around 205°C: light brown beans, used to emphasise the characteristics of particular coffees.

Medium roasting

Medium roasting seeks a balance between origin flavour and roast development. Some bitterness appears, while acidity becomes less prominent. The approximate range described here is 210–220°C.

• American roast — around 210°C: a moderately brown bean that remains relatively light, often retaining noticeable acidity.
• City roast — around 219°C: a fuller brown colour and a balanced cup in which both the beans' natural character and the effects of roasting are apparent.

Dark roasting

At darker levels, beans become dark brown to almost black, surface oils become more apparent, roast bitterness grows and perceived acidity falls. The reference range here is around 225–250°C.

• Full City — around 225°C: a developed roast, sometimes with the beginning of a surface sheen, around the approach to second crack.
• Vienna — around 230°C: dark brown beans with visible oils, some bitterness and occasional caramel-like notes, while a little acidity may remain.
• French — around 240°C: very dark, oily beans with little perceived acidity. Roast flavour largely masks the original aromatic character.
• Italian — around 245°C: almost black beans, with a strong roast flavour and dominant bitterness.
• Spanish — around 250°C: extremely dark, charred-looking, oily beans with pronounced bitterness. This is a very severe roast level.

What about caffeine? Roast colour alone is not a reliable guide to the caffeine in a cup. Bean species, dose and brewing matter greatly, and measuring by weight or by scoop changes the comparison. A dark flavour does not necessarily mean more caffeine, nor does a very dark roast automatically mean very little.

Roasting coffee at home

If you want to explore roast development yourself, home roasting is one option. Two familiar approaches use an oven or a frying pan. It takes judgement and attention, and purpose-built equipment offers better control.

Safety first: roasting produces smoke and loose chaff and can pose a fire risk. Ventilate well, never leave the beans unattended, use heat-safe equipment and oven gloves, and avoid paper or other materials that could ignite at roasting temperatures.

In the oven

Spread green beans in an even layer on a suitable metal tray and place it in an oven preheated to around 230°C. Fan circulation can help, though ovens vary. Stir carefully at intervals to encourage even roasting.

After roughly ten minutes, depending on the oven and batch, you may hear the first “crack” as the beans change. Watch the colour and aroma rather than relying only on a timer. Remove the tray at the desired stage and cool the beans promptly using a safe, heat-resistant setup.

Experiment with small batches and record the results. A medium roast is generally developed after first crack and before a strongly developed second crack; waiting well into second crack takes the coffee towards darker roasting.

In a pan

Use a suitable heavy pan and a small, even layer of green beans. Keep them moving continuously over controlled heat until the desired colour develops, then cool them promptly. This hands-on method requires particular care to avoid scorching or an uneven roast.

If you would like to experiment, explore the green beans in our selection. If you prefer us to roast your coffee, you can enquire about the available roast options for our Arabicas when ordering.