On the long road that coffee beans take before they become the fragrant beverage in your cup, coffee roasting is the most important stage. Skilled roasting is fully responsible for how the taste and flavor characteristics of coffee beans are manifested. Experts claim that there is an exact method that will extract from coffee bean all of their secrets and achieve absolute genuine taste. The art of roasting is achieved by long practice and endless experiments. Get the exclusive taste of coffee, based on substantial experience and advice of highly qualified experts in the coffee business.
Roasting is done in a special machine – a roaster. This is an oven in the form of a drum, the rotation of which provides intensive mixing of the beans. The dimensions of the machine depend on the production volume and can vary significantly. Roasters are equipped with sensors, which allow controlling the roasting. There is a special scoop for taking out sample beans and check their quality. When the beans are roasted, they are cooled by a stream of cold air. Roasting green coffee is a dangerous and delicate process. If you over-roast them, the coffee acquires a bitterness due to charred sugar and its value is significantly affected.
What happens to the grain in the process of roasting:
- Subjected to a high temperature, the green coffee beans lose moisture and grow in size.
- The browning of the beans is caused by sucrose converting to caramel during roasting.
- Cafestol, another complex substance formed during roasting, is responsible for the specific coffee aroma.
- Essential oils leave the beans during roasting, which changes the structure of the beans.
The “Two Claps” Rule
“Claps” is a particular term used to denote the stages of professionally roasted beans. In the first minutes, the beans change color, but still remains pale yellow, and the original grassy smell of smoke turns into a more distinctive aroma. Its appearance is accompanied by the first “cotton” – a clearly distinguishable crack, which signals the beginning of the active caramelization of sugars and removal of essential oils. At this stage, the oven is heated to 170°C. The longer the roasting process, the greater the allocation of oil and the more fragrant the coffee gets. The most intense taste and aroma of the finished beverage will be from those beans that have been allocated the largest amount of essential oils. This effect is achieved only after the second “cotton”, when the beans become darker in color, the density of the smoke gets thick, and the sugar burns entirely. The temperature reaches 230°C.
Tostado ligero beans have higher acidity and a sharp taste. Dark roasting coffee beans reduces the amount of caffeine in them and enriches the taste, but the re-roasted beans take on a burning charcoal flavor. The uniqueness of each variety of coffee requires an individual approach to its roasting, since different beanns behave in different ways when roasting, meaning differences in the temperature and cycle times. To achieve the unmatched and unique taste of coffee that delight connoisseurs of the drink every morning, beans taken from different stages of roasting are combined in different proportions to create the best possible flavor.
The primary methods of coffee roasting
As you know, coffee roasting is an art, so there aren’t any clearly defined and established standards that are sharing roasting. Nevertheless, there is a clear division between weak, medium and sharp roast. True connoisseurs aren’t limited to these three options, but have many more. Consider the most popular ones, and take into account the national traditions of different countries.
- Light roast (Scandinavian, cinnamon, New England, semi-urban)
The lightest roast (195-205° C) leaves beans of a bright brown color and gives a slightly pronounced aroma of bread. This method is applicable only for frying gentle mountain grades of higher quality Arabicas. Coffee made from beans of light roast will be sour in taste and have a watery consistency. It’s not good for making Espresso, but goes just fine with cream and milk.
- Medium roast (American, brown, medium brown, regular)
This roast is achieved immediately after the first “cotton” which occurs when the heating temperature reaches 210-220° C. At this temperature there is very little isolation of vegetable oils from the beans. Prepared coffee will have a characteristic taste of caramel with slight acidity, and some herbal tones. The aroma of medium roast coffee is already pronounced.
- Viennese roast (urban, business, light French)
The Viennese coffee roast reports a second “pop”. This is due to active selection oils that are formed on the bean’s surface which turns dark brown. The bean acquires a clean bitterness in taste, with moderate to fully sweet notes. Espresso is typically brewed from this type of roast.
- Strong roast (French, Continental, New Orleans)
Coffee beans are subjected to even more active roasting up to 240° C. The beans turn dark brown, similar to the color of dark chocolate, and have a significant amount of oil on the surface. The bitter taste of the coffee becomes more tangible. French roast coffee gives the finished beverage strength, saturation, and density.
- Spanish (Italian, Cuban) roasting
The strongest roasting requires much skill. Italian coffee roasting takes place at a temperature of 245-250° C, which all varieties of coffee bean cannot bear. The color is almost black and the beans become very oily. There is no acidic taste in the coffee, but the flavor will have smoky, caramel notes. This option is best for foodies who love bitter coffee with a long aftertaste.
How to roast coffee at home
To roast coffee at home, follow these steps:
- Thoroughly rinse the green beans under running water or even hold them in water for up to ten minutes.
- Dry the coffee beans by placing them on a towel or napkin.
- Heat a clean cast-iron frying pan, add coffee beans in a layer no thicker than 2-3 cm and set on low heat.
- Continuously stir the beans in the pan with a wooden spatula throughout the roasting process.
- When you hear the first “cotton” — characteristic sound — roast the beans until they reach the desired color. Check readiness by sampling a bean.
- The finished fried bean should be placed into a container for 6-12 hours with the lid cracked. Do not grind until ready to use.
Essentials to know!
If you are new to coffee roasting and just starting to experiment with it, do not forget to take into account a few simple guidelines:
- Roasting coffee at home will require you to bear in mind that coffee beans swell from the heat, and after you have completed the process, they will not shrink to their final size until they have completely cooled down.
- Coffee beans, like a sponge, absorb any odors. It is advisable to use a roasting pan that has not been used for other purpose.
- The harder you roast the coffee, the less caffeine will be left in it.
There is no single answer to the question: “How do you roast coffee?” To decide how much should roast grains of various types, you’ll have to research other people’s advice, which of course will be based on their own taste preferences.