Comparison of Agtron value and roasting degree of coffee beans the difference between coffee bean powder color value and coffee bean surface color value

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Many coffee shops that roast their own coffee beans will display two values, one is the Agtron color value, the other is the Agtron bean powder color value, in addition to showing the coffee origin, altitude, coffee variety, coffee treatment and coffee flavor, some coffee shops will display two values on the coffee bean introduction card or the coffee bean packaging. So what do these two numbers mean? In this article, the front street to talk about what is the bean color value, what is the bean powder color value.

What is Agtron?

The caramelization tester (Agtron) is an optical instrument that uses infrared wavelength to determine the roasting degree of coffee. This instrument can determine the degree of caramelization of sugar on the outside and inside of coffee beans, and present it in a way. Each country has a different view of roasting coffee, lack of unity, so when roasting coffee became popular, there was one way of roasting and another way of baking.

As one of the authoritative representatives of the coffee industry, the American Fine Coffee Association (SCAA), in order to solve this phenomenon that is not debated on the same channel, jointly with Agtron to determine the caramelization of coffee beans at infrared wavelengths to detect the caramel degree of coffee beans, the color is divided into eight equal parts from light to deep to make eight standard color blocks, which can be used by the coffee industry as a baking standard, so that all baking gods can learn from each other on the same "channel".

How does the Agtron value define the depth of roasting of coffee beans?

Agtron color value # 95: light baking (Light Roast)

Time to drop beans: the density of explosion is coming to an end.

Agtron color value # 85: cinnamon baking (Cinnamon Roast)

Time to drop beans: before and after the end of the explosion

Agtron color value # 75: medium baking (Medium Roast)

Time to drop beans: after the explosion is over

Agtron color value # 65: deep baking (High Roast)

The time of dropping beans: the quiet period between the first explosion and the second explosion

Agtron color value # 55: urban baking (City Roast)

Time to drop beans: the second explosion begins.

Agtron color value # 45: city-wide baking (Full City Roast)

Time to drop beans: before the second explosion is dense.

Agtron color value # 35: French baking (French Roast)

Time to drop beans: when the second explosion is dense

Agtron color value # 25: Italian baking (Itatian Roast)

Time to drop the bean: the oil begins to seep out of the bean surface

Qianjie has roughly sorted out the above eight areas. we can roughly divide the degree of baking into light baking (including light baking & cinnamon baking), moderate baking (including moderate baking & deep baking), medium-deep baking (including urban baking & citywide baking) and deep baking (French baking & Italian baking).

Among the more than 50 types of coffee beans on the front street, more than 70% of the coffee beans are mainly lightly roasted. Coffee beans from Ethiopia, Kenya, Guatemala, Colombia, Panama, Costa Rica, Honduras, Tanzania, Bolivia, Yunnan, China and other producing areas are all baked in cinnamon color. The other 30% of coffee beans, including Brazil, Indonesia, Kona, Hawaii, the Blue Mountains of Jamaica, Papua New Guinea, Mexico and Italian coffee beans are moderately roasted.

What is the bean color value? What is the bean powder color value?

The color value of beans means that after the coffee beans are roasted, the original particles of coffee beans are determined by infrared caramelization, and the degree of roasting on the surface of coffee beans is judged from the surface of coffee beans. But the baking degree of the surface can not determine the baking degree of the whole coffee bean is consistent, it may be due to excessive firepower in the baking process, resulting in serious caramelization on the surface of the bean, but the interior of the bean may not reach the corresponding standard value, so the standard of Agtron value is the caramelization value of a coffee bean after grinding (that is, the color value of bean powder) as the standard.

The color value of bean powder, as the name implies, is that after the coffee bean is ground, the color value of the coffee bean core, and the color value of the bean core has reached the Agtron numerical standard, then it can be said that the roasted beans have reached the corresponding degree, because only the bean surface and the bean core are uniform inside and outside, the flavor of the coffee beans after brewing will be stable. If only the bean surface is caramelized and the bean core is not even caramelized, there will be bitter and green coffee flavor. This also represents the "rollover" of the baked beans.

Does the degree of roasting affect the acidity of coffee beans?

When guests ask if there are sour coffee beans on the front street, the baristas on the front street will recommend cinnamon roasted Kenyan coffee beans or Ethiopian coffee beans; when guests ask if there are any unsour coffee beans on the front street, the barista on the front street will recommend medium-roasted Brazilian or Indonesian coffee beans.

Why is that? The roasting degree of coffee will affect the acidity of coffee to some extent, the deeper the roasting degree, the less acidity of coffee. This is because during the baking process, caramelization will gradually produce bitter substances, such as chlorogenic acid lactone and phenyllindane, and as the baking degree increases, these products will increase, especially after the second explosion. So those who like sour coffee can choose coffee beans that are lightly roasted, and those who like mellow feeling can choose coffee beans that are moderately roasted or above.

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