Does the coffee with clean hands taste good? What is the cause of the turbid coffee liquid?

Usually, when we make coffee, we pay great attention to the parameters and techniques. When tasting, we also pay great attention to the flavor and taste. But few people talk about the soup color of coffee liquid.

The color of soup is the color of tea, which comes from the professional term of tea commentation. according to the method, the tea with different degree of fermentation has different standard color, and one step in the evaluation of tea is to observe whether the color of the soup is standard or not, and to distinguish the advantages and disadvantages in terms of transparency. If you carefully observe the drip-filter coffee filtered by filter paper, you can also use "soup color" to see some information. Dark and light black and red coffee soup color generally from red to black this range, mainly formed in two aspects, the first is the concentration, the higher the concentration of coffee, the darker the soup color, the lower the concentration, the lighter naturally. The second is the roasting degree of the coffee. If you are careful, you will find that basically the coffee liquid from the medium-to-light roasted coffee beans will be black and red, while the medium-and deep-roasted coffee beans will be dark.

The lighter ones are clearer? The darker one is more muddy? Many people will think that the lighter the color of coffee is, the brighter it is, but it is difficult for dark color to have that kind of "crystal clear" effect. In fact, the clarity of coffee has little to do with the depth of color and the concentration of coffee. The reason for the turbid feeling of coffee liquid is related to the degree of water solubility of the extracted substance. The first thing to talk about is the filter apparatus. At present, there is not only a kind of coffee filter like filter paper. If you open an online shopping platform, you can also find metal filter mesh, flannel filter cloth, and even filter-free paper filter cups (tea leaks).

Not all filtering appliances have very good performance, such as the large gap in the metal filter, which can pass through some substances that are insoluble in water, which will make the coffee liquid turbid. The second is to use filter paper with good filtering performance, the water quality and the fine powder of coffee are also likely to cause coffee turbidity, when the water contains high tds content, the coffee will be relatively turbid, if the coffee is soaked for too long, it will also release some macromolecules, which will make the soup color look opaque. Another situation is that the freshly brewed coffee is very clear and the coffee liquid becomes cloudy after it has been placed for a period of time. One reason is that the change in temperature makes the originally dissolved substance insoluble.

Moreover, caffeine and chlorogenic acid are easy to combine, and once combined, they become insoluble in water, so the coffee liquid generally becomes turbid after cooling, mostly on lightly roasted coffee beans. So, clear coffee tastes good? Turbid coffee tastes bad? This also depends on the situation, generally normal brewing shows a clear color of coffee soup, except for the coffee beans themselves, basically tastes good, but not too transparent coffee does not mean bad or bad. For example, the deep-roasted coffee filtered by flannel is basically opaque, and there is a layer of oil (film) on the surface, but it is also a cup of coffee with great charm.

And the coffee that turns turbid after cooling is also expected to taste bad.