Understanding the Maillard Reaction in Coffee Roasting

Maillard Reaction is one of the chemical changes during coffee roasting. This chemical reaction occurs between amino acids and sugars in the presence of heat to produce a wide range of flavor compounds that contribute to the complexity of the coffee’s overall taste. The Maillard Reaction is crucial for flavor development as it creates depth and richness in coffee flavor, similar to browning in cooking.

 

The Science Behind the Maillard Reaction

Maillard Reaction is named after Louis- Camille Maillard, a French chemist who published a scientific paper describing the reaction in 1912. Any food item that contains proteins (amino acids) and carbohydrates (reducing sugars) can trigger a Maillard reaction when heated. To put it simply, Maillard reaction can be described as:

How does Maillard Reaction work in coffee roasting?

Coffee beans go through three different stages during roasting: the drying phase, the browning phase and the development phase (where the first crack happens as the beans release steam). The Maillard reaction in coffee roasting occurs during the second phase, where the caramelization process also happens at the same time. During this phase, the coffee beans undergo chemical changes that enhance their complexity and aroma, defining their final flavor profile.

According to the American Chemical Society, from temperatures between 150°C to 200°C, carbonyl groups in sugars and amino groups in proteins inside the coffee beans react to form the aroma and flavor compounds. This Maillard chemistry forms hundreds of coffee flavor compounds, including 2-furfurylthiol which is the robust coffee aroma and flavor compound. The extent of the Maillard reaction varies depending on the degree of coffee roasting determined by the coffee roaster, from a lesser extent of Maillard reaction on light roasts to an extensive one on dark roasts.

 

Factors Influencing the Maillard Reaction

There are several factors that may influence the Maillard reaction in coffee roasting:

1. Temperature and time

Temperature plays a critical role in starting and controlling the Maillard reaction, as different compounds are formed at different temperature ranges. Time is also an important influence, as a longer Maillard reaction has a significant impact on the flavor profile. A coffee roaster carefully monitors their roast and seeks to find balance between temperature and time to unleash the full potential of the Maillard reaction on their green coffee beans and achieve the best coffee flavor profile.

2. Bean moisture content

The moisture content in the green beans strongly influence the rate of the Maillard reaction. A certain amount of moisture is needed in the coffee for the Maillard reaction to happen, and can also influence how the coffee aroma is produced. As a rule of thumb, green coffee beans with a higher water activity may have a quicker response to heat during roasting and may have an increased rate of the Maillard reaction.

3. Bean type and origin

Each coffee bean has unique characteristics based on its type and origin. On a molecular level, these characteristics are represented in different compositions of sugars and proteins in varying degrees. This composition is related to the flavor development of the coffee beans during the coffee roasting process, through the Maillard reaction.

 

Optimizing the Maillard Reaction

To successfully achieve the flavor profile that they are aiming for, coffee roasters optimize the Maillard reaction by doing the following:

• Controlling airflow
• Adjusting roast temperature
• Monitoring roast progression
• Know your coffee beans’ origins and characteristics
• Master your coffee roaster machine

By implementing these key strategies, you can use Maillard reaction to unleash your green coffee beans’ true potentials and achieve their ultimate flavor profile.

Berto roaster machine is an essential instrument in bringing this goal into reality. Enabling a coffee roaster’s work to be as seamless as possible.

Understanding roasting phases, controlling temperature and airflow, and diligently monitoring data have never been easier. Achieving consistent, exceptional results, have never been smoother. What are you waiting for? Speak to our team today and get the best Berto roaster for your business.