``When making coffee, it's better to wet the beans with water before grinding them,'' research backs it up.

Coffee lovers have devised various ingenious ways to make delicious coffee at home, including a technique called `

`wetting the coffee beans a little before grinding ''. A study conducted by a research team at the University of Oregon in the United States showed that wetting coffee beans actually suppresses the static electricity generated when grinding, making it possible to extract coffee more efficiently.

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Some coffee lovers recommend that you wet the coffee beans a little before grinding them to avoid the static electricity generated when grinding them with a mill or grinder, causing the grounds to clump together and resulting in uneven extraction. 'It's better,' he advises. However, the details of how static electricity actually affects coffee beans when they are ground, and whether the amount of static electricity varies depending on the condition of the beans, were not well understood.

Christopher Hendon , a computational materials chemist at the University of Oregon, teamed up with Joshua Mendez Harper, a volcanologist at Portland State University , and others to investigate the static electricity generated when coffee beans are ground. Ta.

Although it seems a surprising combination, the charging process during volcanic eruptions that Harper, who served as the lead author of the paper, is studying is similar to the charging process when grinding coffee beans. Harper said: 'During an eruption, magma breaks down into many small particles that erupt from the volcano in a large plume of smoke. All the while, the particles rub against each other and become electrically charged enough to create lightning. 'Simplistically speaking, this is the same as grinding coffee beans into a fine powder.'

The research team analyzed the amount of static electricity generated when grinding coffee beans with a grinder using coffee beans of various countries of origin, processing methods, roasting degrees, and moisture contents.

The researchers found that the degree of roasting and moisture content of coffee beans are related to the amount of static electricity generated during grinding. Specifically, beans that are more deeply roasted and have a darker color have less internal moisture and generate more static electricity during grinding, while beans that are lightly roasted and have a lighter color have more internal moisture and generate less static electricity. It has been reported that this is less likely to occur.

Next, we investigated whether the extraction time and flavor of the coffee would change if the same coffee beans were ground dry in a grinder and extracted in an espresso machine, or if they were wetted and ground into powder.

They found that wet coffee beans take longer to brew and produce stronger coffee. Additionally, wetting the powder with water makes it less likely that the powder will be uneven, which will help reduce the differences between shots.

Hendon says, 'It's not about the origin or the processing method. It's not about the quality of the coffee or the price of the beans. It's about the color and the moisture inside the coffee.' In response to an interview with science media New Scientist, Mr. Hendon answered that adding 0.5ml of water per cup of coffee (20μl per gram of coffee beans) can prevent the powder from clumping and improve the flavor of espresso. Did.

In this study, only espresso was tested, but the benefits of wetting the coffee beans to reduce static electricity and prevent the powder from clumping are also beneficial for other coffee brewing methods. This method also allows for the extraction of more concentrated coffee from the same amount of coffee beans, which could have a significant economic impact on the coffee industry as a whole.

In the future, the research team plans to conduct further research on ``the perfect way to make coffee.'' Hendon said, ``Now that we know how to grind coffee beans to make reproducible espresso, we want to understand what causes the sensory differences in the taste of coffee.'' ” states.

It is also hoped that interdisciplinary collaborations centered around coffee will provide insights into the earth sciences. 'There's still a lot we don't know about how coffee beans are ground, flow as particles, and interact with water,' Harper said. 'It may also be useful in solving parallel problems in geophysics, such as the penetration of carbon dioxide.'

in Science,   Junk Food, Posted by log1h_ik