Everything you need to know about roasting coffee

Everything you need to know about roasting coffee

It has now been more than a year that I’ve joined the rank of the Maxicoffee team! Needless to say, I’ve learned a lot about coffee. However, I have to admit that, even after all this time, the roasting process remained a nebulous subject for me! So without wasting any more time, I went to see the coffee roasters at Cafés Lugat to learn more about this process!

Before tell you everything you need to know about roasting coffee, let’s just pause for a second to think about what is really means. The roasting process is the art of transforming green coffee into the precious nectar that we call “coffee”. But before drinking our cup of Joe, the green beans need to go through several stages.


Green coffee beans before roasting


The three main stages of the roasting process

Drying stage

The drying stage starts when the green coffee beans enter the drum roaster until they change colour. Indeed, the coffee beans will turn yellow as they dry which is called the “Stucker reaction“. This reaction is due to the evaporation of the humidity naturally contained in the green coffee beans (8 to 12% humidity).

Browning stage

At the end of the drying stage, the temperature reaches 160⁰C which leads to the browning stage; this is when the “Maillard reaction” begins. This reaction allows for the aromas to develop. Consequently, the longer it lasts, the better the aromas will be. Therefore, the roast can be slown down in order to ensure powerful aromas in cup. The aromas go from notes of hay and toasted bread to more fruity notes. The coffee beans slowly go towards a light brown colour.

Development or roasting stage

The end of the browning stage starts with the first “crack”, and this is the moment that the development stage begins. It allows the aromas’ stabilisation and gives the coffee beans their final colour. This is the most technical stage of the roasting process since the roaster has to choose when to stop the roasting process in order to acheive the right roast degree and the right flavour profile.

Crack : the explosion of a coffee bean due to extreme pressure. It results in the evaporation of the water contained in the coffee beans.

These three stages will enable the coffee roasters to work on various coffee aspects:
• Its body.
• Its sweetness.
• Its acidity.
• Its aromatic profile.


coffee beans roasting stages

My three favourite coffees:

Very Light Roast: Moka Benti Nenka – Microlot from Ethiopia

Light Roast: Clave de Sol – Microlot from Honduras

Organic Medium Roast: Altura – from Peru

Let me know what you think about these coffees thanks to the following discount code, CAFESLUGAT05, that will give you 5% off these coffees !

One word: precision


The roasting process is a work of precision. Indeed, the end result can be completely different with a variant of temperature of just one degree or with a shorter or longer roasting time.
It is therefore on the coffee roaster to determine the precise roasting time and exact roast temperature during the three stages of the roasting process.


Lionel at the roastery, roasting coffee beans

The different types of roast

Contrary to what you would think, it is the final result in cup that determines the right roasting process. For example, an espresso roast will be different to the roast specific to slow coffee (i.e. filter, pour-over, French Press, etc). In order to obtain the right result in cup, coffee roasters can go with three different roasts.

Depending on the desire roast, the length of the roasting process will be between 7 and 30 minutes.

Light roast = 8 to 12 minutes

This roast will offer floral and fruity aromas with more acidic flavours. Usually, the goal is to find the perfect middle ground between a roast not too light and not too dark. That is why a very light roast is complex to obtain, but it is worth trying since it can bring surprising aromas. The complexity lies in gaining the right aromas in order to avoid hay, green beans and cereal aromas which would indicate that the roast is too light.

A light roast is generally chosen for filter coffee and other slow coffee methods but can also be adopted by sharp espresso lovers!

Medium roast = 12 to 15 minutes

A medium roast will bring a good balance between acidity and bitterness. You’ll experience more chocolatey and nutty flavours. The goal of a medium roast is round the fruity and floral aromas into sweeter and more gourmet flavours! Thanks to this balance, a medium roast will be less acidic compared to a light roast. If brewed with a filter coffee machine, you’ll obtained a full bodied coffee and a dash of bitterness.

Dark roast = More than 15 minutes

Generally, a dark roast is chosen by Italian coffees intended specifically for espressos. The aromatic profile will tend more towards hazelnuts and toasted bread. The bitterness will be quite important and the acidity quite low.

Do you know how a coffee roaster determines that the coffee beans went from medium to dark roast? With its darker colour, it is also the second ‘crack’ that gives it away!


medium to dark roast coffee beans

Now I gave you everything you need to know (almost) about coffee roasting! Don’t forget that just like you can’t determine what is the the best coffee, you can’t have the best roast! The best roast is the one that suits you best!

Coffee roasting at Cafés Lugat

Our team of coffee roasters is dedicated to make you discover all the diversity of the coffee world. We want to show you that a coffee can be roasted in different ways in order to give you a plurality of aromas in cup. With Cafés Lugat, you’ll be able to experience three types of roast: very light, light and medium roast.

At Cafés Lugat, we are constantly looking to achieve the perfect roast for each coffee in order to sublimate the origin of each coffee. That’s why we are committed to traceability of each farms, to fair trade with the producers and sustainable development.

We want to share our passion for coffee in order to make good coffee accessible to all!

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