In Japan, coffee has been consumed in large quantities for a long time and is a popular beverage in our everyday lives. Freshly brewed coffee at convenience stores has recently expanded its market presence in this context. This paper describes the extraction technology of coffee machines to support freshly brewed coffee at convenience stores. The history of coffee and the extraction technology will be firstly introduced with the background of how we chose drip coffee, followed by the description of the technology for design of the coffee machine. The challenges for machine design were, of course, to make tasty coffee and to serve it stably and quickly with ensuring good hygiene, and, furthermore, maintenance of its function for a long time. We have been able to meet these demands by developing technologies for the coffee mill (i.e., grinder) and coffee brewer (i.e., extractor) which are the most important components of the machine. For the coffee mill, we achieved good taste of coffee with less miscellaneous unpleasant flavors and tastes by stabilizing the particle size of the ground coffee beans and reducing heat generation, and we then standardized the quality of the beverage by taking measures including anti-static electricity. For the brewer, we have also improved the technologies such as mixing hot water and ingredients, stirring them and using pressurized extraction of coffee to achieve rapid and stable extraction. The technology for high volume extraction which has been increasingly demanded in recent years has been developed as well.
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