Jacobs Douwe Egberts R&D GB, Limited , Ruscote Avenue , Banbury , Oxfordshire OX16 2QU , United Kingdom.
Centre for Formulation Engineering, Department of Chemical Engineering , University of Birmingham , Edgbaston, Birmingham B15 2TT , United Kingdom.
J Agric Food Chem. 2018 May 30;66(21):5301-5309. doi: 10.1021/acs.jafc.7b04848. Epub 2018 Apr 23.
This paper describes new results from a base model of brewing from a bed of packed coffee grains. The model solves for the diffusion of soluble species out of a distribution of particles into the flow through the bed pore space. It requires a limited set of input parameters. It gives a simple picture of the basic physics of coffee brewing and sets out a set of reduced variables for this process. The importance of bed extraction efficiency is elucidated. A coffee brewing control chart has been widely used to describe the region of ideal coffee brewing for some 50 years. A new chart is needed, however, one that connects actual brewing conditions (weight, flow rate, brew time, grind, etc.) to the yield and strength of brews. The paper shows a new approach to brewing control charts, including brew time and bed extraction efficiency as control parameters. Using the base model, an example chart will be given for a particular grind ratio of coarse to fine particles, and an "espresso regime" will be picked out. From such a chart yield, volume and strength of a brew can be read off at will.
本文描述了一种从咖啡颗粒床层中酿造的基础模型的新结果。该模型求解可溶性物质从颗粒分布中扩散到通过床层孔隙空间的流动中的扩散。它需要一组有限的输入参数。它为咖啡酿造的基本物理提供了一个简单的描述，并为这个过程提出了一组简化变量。阐述了床层提取效率的重要性。咖啡酿造控制图已经广泛用于描述理想咖啡酿造的区域约 50 年。然而，需要一个新的图表，它将实际酿造条件（重量、流速、酿造时间、研磨等）与酿造的产量和强度联系起来。本文展示了一种新的酿造控制图方法，包括酿造时间和床层提取效率作为控制参数。使用基础模型，将为特定的粗颗粒与细颗粒的研磨比给出一个示例图表，并挑选出“浓缩咖啡”范围。从这样的图表中，可以随意读取酿造的产量、体积和强度。
