Strictly speaking, coffee roasting is controlling a simple chemical process, or as Wikipedia put it …
Roasting coffee transforms the chemical and physical properties of green coffee beans into roasted coffee products. The roasting process is what produces the characteristic flavour of coffee by causing the green coffee beans to change in taste.
… saying that, currently there is an artisan approach to the coffee roasting process, so now a simple cup of coffee at the office is the end result of years of coffee roasting experience, very expensive roasting machinery; not to mention a great office coffee making machine at the end. Read our introduction into the dark art of the coffee roaster.
Let’s have a brief view into the amazing process of the different stages of roasting coffee beans, shall we? You see, coffee beans aren’t really coffee, as we know it until they are roasted. The make-up of the bean is the same, from its unique qualities to its caffeine content, but the flavour you taste in the cup isn’t available until it is roasted. The real art of the roaster is to find the perfect balance of roasting to bring out the bean’s most authentic flavour.
The Popping Sounds
There are several different methods and recipes for roasting, but they all rely on certain combinations of heat and time to get the very best out of the roasting process. Many people have compared the process of coffee roasting to that of popping popcorn; as the beans quite literally pop when they are heated to a certain temperature. Actually, the process involves two pops! (1) That’s water and oxygen escaping the bean in the first pop; (2) carbon dioxide escapes in the second pop.
Aplying The Heat
As the bean roasts in temperatures ranging from a balmy 188° C degrees to an extremely hot 305° C degrees it changes the colour of the beans from its natural green, through to shades of tans and medium browns; all the way to dark, chocolaty brown (bordering on black). If the process is allowed to run for too long, all that’s left is a carbonised lump of ash.
Basically, there are two types of coffee roasters, though their sizes and capacities vary greatly. These types of machine are:
- The first and oldest type of roaster – is the drum roaster. With this type of machine, coffee beans are loaded into a drum or cylinder-shaped chamber; which is lain on its side. As the drum rotates, either gas or electricity – (sometimes) even an open flame (if you’re truly daring) heats the tumbling beans from below.
- The second type of roaster is the air roaster, which utilises a rapid flow of super-heated air. Roast time is dependent on each roasters unique recipe.
The roasted beans are then cooled either using a vacuum system or a water mist process known as quenching. Cooled beans are quickly packaged, sometimes in foil bags that allow them to “de-gas”. From here, maintaining freshness for our customers is critical: the roasted beans are swiftly and conveniently shipped directly to you for your enjoyment. An amazing fresh cup of your favourite brew, roasted to order with great care and love. Ah, I can taste it already!
The Art of Roasting
The art of roasting is in determining how much time and resulting colour best suit the bean. There is a point; however, when the flavour overtakes the bean’s original flavour, the roasting gives it. Hence, darker roasts, a quality preferred by some drinkers taste less like their original bean. Light and medium roasts find a balance to capture the bean’s qualities and flavour notes as determined by a bean’s geographical origin or variety. If you want to know, for example, how Kona coffee truly tastes, best not to roast it too much.
It’s the colour of the roast, not the taste of the coffee that gives this roast its name. This stage is also known as a pale roast or New England, the mildly flavoured beans are usually roasted to this level to protect their delicate tastes.
Also known as the American roast, the beans are roasted to a light to medium brown colour. This is used with many everyday coffees to produce a richer, even sweeter flavour that many prefer.
Also considered a Medium roast, the finished bean has a medium brown colour with a slightly oily texture. This is a very popular roasting [type] to retain the original flavour character of the bean.
Full City Roast
This roast produces a medium dark brown colour with an oily texture to the finished bean. Sweetness and acidity wane, the brew becomes heartier in character, more chocolaty.
Considered the first of the dark roasts, sometimes lumped in with French Roasts, the bean finishes with a dark brown, shiny colour and oily texture. This roast is often used for espresso coffee, the original flavour character of the bean is now surpassed by the flavour of the roasting process.
The heart of the dark roasts, the bean is very dark brown at the finish. The brew has a smoky, burnt flavour, very low in acidity level. This is one of the most popular roasts for espresso makers.
Almost black coloured roast, with a somewhat brittle texture to the imparted to finished bean. Very little character of the original bean remains with this type of roast, so this roast, as with other dark roasts, can be used to mask inferior, low-quality beans.
Also known as Dark French or Neapolitan. These extremely dark beans are nearly black in colour with a shiny, oily appearance and boast a strong, charcoal flavour. Definitely an acquired taste.
Coffee Machines For Your Place of Work
At coffee4business, we specialise in coffee machines & beverages suited to workplace environments. Whether your business is small, medium, corporate, industrial or retail, we can offer sound professional advice based on many years experience.
We supply coffee machines and their accessories, quality coffee beans and other consumables and also water filtration units. Whatever your workplace beverage needs, we can offer professional advice!