How Are Coffee Beans Roasted?

How Are Coffee Beans Roasted?

 

It has been purely coincidental that I have been asked by several people recently as to what is the roasting process and what makes Espressopedia Italian coffee so different.?

The short answer is: raw coffee beans are dropped into loaders and then fed into a rotating drum. The drum has been pre-heated to a temperature of around 240 degrees, for an Italian roast. After 12-15 minutes the roasted beans will exit the drum at around 195 degrees and are then taken out into a cooling tray at the front of the roaster. They are then passed through a machine that removes any stones or debris before being checked by hand for any defects, and once cooled completely, finally packaged into bags or ground to go into the pods that line the shelves in my house, ready for sale.

 

 

The long answer on how to get to get from the sack to the pod:.

 

Firstly, the beans are loaded into a drum inside the roaster, which rotates over gas burners and agitates the coffee beans. Italian Coffee for Espresso Lovers (the only brand we sell at Espressopedia) produce both single country origin espresso coffees as well as their own original blends. The roasting process will take around 12-15 minutes using 3 ½ kilos of raw green beans. It is a washed process which means that when the coffee fruit is picked, all the fruit pulp and skin is removed before the drying process. This makes the coffees really clean and balanced with lots of sweetness.

 

In the early stages, the roast can smell quite straw-like. Obviously the senses need to be tuned in to the roast, this can be difficult with all the other scents wafting throughout the roastery, but fortunate for us Michele has two decades of experience. This is how you really learn to roast coffee, without the aid of software, sensors or dare I say it artificial intelligence.

 

In the espresso roast it takes a little longer to extract more of the sweetness and body from the bean, so that it stands up better to the intensity of espresso brewing. This pushes the sugar development further which is how you can achieve that extra sweetness in the flavour.

 

One of the biproducts produced from roasting is called ‘chaff’. This is the final layer that surrounds the seed of the coffee cherry, as the beans get hot they shed this jacket like the husk of a nut. These are collected and recycled in composts or a more recent development is to use the skin of the coffee cherry to make tea, which is known as 'cascara' (pictured below).

 

 

 

  

The coffee beans start to expand as they get hot, developing a mottled yellow hue. The beans are taking on more energy as heat (endothermic) as they roast, when they reach a point when they can no longer take on any more energy the reaction becomes exothermic (they release heat). This is a key time as the coffee starts to develop all the sugars and oils it needs to take on the full-bodied espresso flavour. It's also a crucial time in terms of adjusting with the heat that is brought into the roast. The coffee is browning because the natural sugars are caramelising on the bean. When this happens it starts to produce that pleasant, malty smell, that we all associate with coffee roasting. Though this roast is smelling great, the beans are quite a long way from the finished product.

 

As the coffee beans expand further with the heat and the pressure they start to produce their own heat and make an audible 'cracking' sound. This stage is known as 'first crack'. This is usually time to turn the gas down, to compensate for the heat exuded by the beans. As this is an espresso roast however, the heat goes back up until the second crack. The beans are monitored very closely, and when roasted to the optimum colour and level of development, they need to be stopped from roasting any further via a cooling process.

 

 

Cooling The Beans

 

The beans are then released into a cooling tray beneath the door of the roaster. The beans are rotated to keep them evenly distributed while air is drawn through small holes to cool the beans evenly.

 

Espresso roasts like this tend to last a bit longer than filter coffee roasts, but they can also be too fresh. When the coffee is very fresh, there is still a lot of gas within the beans which can be quite volatile during the extraction process, making it quite lively and acidic in the taste.

 

The coffee is left for 7-10 days after the roast date to remove that acidity but the coffee can be good for a month, or even two depending if it has been stored well.

 

It is after the 7-10 days period that the beans are eventually ground at the Padua factory and packaged into the individual pods before being boxed and shipped to Espressopedia.