New! Custom roasts tailored to your taste.
Explore and savour different coffee terroirs with our custom roasts. You can now tailor the organoleptic development — the aromas, flavours and textures — to your choice of roast. We are proud to offer a variety of rare and richly flavoured terroirs.
The following table indicates coffee aromas according to desired roast levels. Our roasting parameters aim for a balanced ratio of acidity and bitterness that allows the terroir’s flavours to develop gently. Remember that appreciating different aromas in any gourmet food, such as wine, spirits, beers, and cheeses, remains personal.
How to purchase your custom roast coffee
Once you’ve selected a terroir, choose your preferred roasting level using table. We will then roast your coffee according to your terroir selection and desired roast. (Please note that availability of terroirs may vary depending on market supply).
To maintain quality, you must order a minimum of 1000 grams of green coffee to obtain 800 grams of roasted coffee. To preserve freshness, we will send two 400 grams bags of coffee, beans or ground, according to your preference.
Basic notions about coffee roasting
Transformations during the roasting process
Transforming raw beans (green coffee) into a finished product is undoubtedly one of the most complex steps in coffee production.
Green coffee beans have nothing in common with roasted coffee’s smell, taste, or appearance. Once roasted, the raw grains undergo a major transformation that reveals more than 800 new identifiable organoleptic components. Nearly a third represents aromatic components that are essential to its aromatic complexity.
Green coffee has a moisture content between 10 to 12.5%, which considerably decreases during the roasting process. Generally, roasting is characterized by three important phases: golden coffee, first crack, and second crack. Each phase has several degrees of roasting colours (we use the Agtron measurement reference scale). Coffee reacts to the following chemical reactions : pyrolysis, the Strecker reaction, caramelization and the Maillard reaction , which we describe here.
Transformations overview during the roasting process
Golden coffee
When lightly roasted, green coffee turns golden, but its texture remains the same. The roasting degree ranges between 80 and 70 according to Agtron values. The roasting process ends before the first crack.
The first crack
At the beginning of the roasting process, a significant drop in temperature occurs as the beans quickly absorb the ambient energy. This first phase of roasting is completely endothermic. At this stage, the heat allows moisture to dissipate.
First, the coloured plant components such as chlorophyll and anthocyanins begin to break down, and the bean’s colour changes from green to golden. This transformation is usually accompanied by a subtle change in aromas, transforming from grassy to toasted notes.
As the temperature increases and stabilizes at around 100°C (212°F), the water begins to form steam and builds pressure in the grain. As the pressure increases, the grain cells rupture, resulting in an audible and repetitive sound known as the “first crack.”
During this stage, the bean can double in size and begins to develop specific coffee aromas. Depending on the extent of the roasting, moisture levels in the grain drop from 10-12% to about 3-5% and a corresponding Agtron value of 75-65.
The second crack
The second roasting phase is accompanied by a shorter, second endothermic stage and a short exothermic stage. During this phase, most of the bean’s moisture content has evaporated, and sugars, proteins, and lipids begin to chemically decompose. Unlike the first crack, which occurs mainly through the formation of steam, the second crack occurs through the formation of CO, CO2, NOx and other gases.
This transformation is normally observed at temperatures between 225° and 230°C (437°-446°F). As with the first crack, a further increase in internal pressure occurs, and the beans begin to take on a shiny appearance due to coffee oils being pushed to the surface. The Agtron value associated with these levels is 45 to 35.
To this day, we continue to discover more about the physical and chemical reactions that occur during roasting.
Chemical reactions
Pyrolysis, or thermolysis, is the chemical decomposition of an organic compound induced by a significant increase in its temperature, thus developing gases and matter that it did not originally contain. The operation is performed without oxygen to avoid oxidation and combustion. This is the first stage of thermal transformation after dehydration.
The Strecker synthesis is named after Adolph Strecker. Strecker discovered and published his findings in 1850 for the first time. He discovered a series of chemical reactions that allow the synthesis of an amino acid from an aldehyde or ketone. These reactions are related to the grain’s pigmentation change.
Caramelization is an organic chemical reaction that results in the dehydration of sucrose and the formation of fructose anhydrides. It is also a culinary technique that consists of polymerizing the sugar in food to acquire a nutty taste and browning without burning or charring.
This is the process by which caramel and caramel colourants are produced. Caramelization occurs when several identical molecules form a single, larger molecule.
The Maillard reaction
The Maillard reaction (MRx) is one of the most important reactions during roasting. MRx is produced when an amino acid and a sugar bond forming several key aromatic and colour components.
Toasted bread and meat are examples of the Maillard reaction in other foods. MRx is non-enzymatic, which means the reaction is triggered by an external energy source such as heat.
The AGTRON system
Developed by Agtron Corporation (Reno, NV), the Agtron scale is the most commonly used reference scale for roast colour classification.
The scale ranges from 25 to 95. It is established by measuring the light reflected by roasted coffee beans or ground. The lower the number, the darker the roast — meaning less light is reflected — while higher numbers indicate a lighter roast. The image below illustrates typical colour degrees.
Références :
Baumlin S (2006) Craquage thermique des vapeurs de pyrolyse-gazéification de la biomasse en réacteur parfaitement auto-agité par jets gazeux [archive] (Doctoral dissertation, Institut National Polytechnique de Lorraine)
(en) F. A. Ishitani, R. E. Reddy et al., « Asymmetric strecker synthesis using enantiopure sulfinimines: A convenient synthesis of α-amino acids », Tetrahedron Lett., vol. 35, no 50, 1994, p. 9351–9354 (ISSN 0040-4039, DOI 10.1016/S0040-4039(00)78540-6).
(en) Hervé This, « Solution to Maillard and grilled steak challenge », Analytical and Bioanalytical Chemistry, vol. 407, no 27, 2015, p. 8173-8174 (DOI 10.1007/s00216-015-9001-y)
Jacques Defaye, José Manuel Garcia Fernández, Valérie Ratsimba, « Les molécules de la caramélisation : structure et méthodologies de détection et d’évaluation », L’Actualité chimique, no 240, novembre 2000, p. 24-27