Commercial importance of coffee
Coffee is the most popular drink in Germany with annual consumption of 162 liters per head of the population. As such, Germany is the third largest coffee market in the world. Annual sales of dry coffee products amount to 5 billion euros (excluding pre-prepared coffee products from industry and 'coffee to go'). Coffee is the world’s second largest trading commodity and is so is very attractive for German industry and for export. Indeed Germany is a leading exporter of coffee products.
Even more astonishing is that although the coffee extraction process has been modeled by various research groups in recent years, there has been inadequate coupling of the findings with actual measurement analytics and no customized product improvement.
More than 1000 companies in Germany deal with 'roast coffee' in one way or another. This includes roasting companies, coffee machine manufacturers, producers of soluble and decaffeinated coffee, and coffee training schools. The model-based optimization of the coffee extraction process could allow new innovative products to be developed.
Factors affecting the extraction process
Coffee is a commodity and consumer product of huge commercial significance. Scientific understanding of the processing chain, from the coffee bean cultivation to the final drink, and of the coffee extraction process still has considerable shortcomings. The preparation of the coffee drink itself is the last chance to influence the quality and characteristics of the final drink. For example, there is nowadays a large selection of mills for grinding coffee and also coffee machines which allow dynamic control of the extraction temperature, water flow, and water pressure. The findings of the project work should enable these parameters to be used in a customized way and potential innovations fully exploited.
Objective of modeling the coffee extraction process
The objective of the project is to use a mechanistic process model to make predictions for customization of the coffee extraction process. The variable parameters here include the water temperature, water flow rate, and particle size of the ground coffee. Comprehensive experimental data will be collected, in particular time series recording the dynamics of the extraction process using different parameters. In parallel, the sensory properties of the coffee drinks will be evaluated. This model will then be used for computer-based process improvement. Predictions will be able to be made as to what water temperature, water flow rate, and particle size need to be chosen to change the coffee taste and aroma in a particular direction. One particular focus will be dynamic process management, enabling for example predictions to be made how the water temperature and water flow rate need to be varied over time in order to achieve an optimal result. The same will be applied for the particle size of the ground coffee. In addition, work is being undertaken to alter the particle size over the height of the coffee packaging.