What is Agtron? What is the effect of different readings of coffee roasting color classification on coffee flavor and taste

Agtron may sound like an agricultural superhero robot, but behind its name lies a simple coffee roasting test: consistency. Agtron uses near infrared light to analyze the color of ground or whole bean coffee. Then output an easy-to-read number that represents the degree of baking. The smaller the number, the darker the roast.

For example, the Agtron reading for espresso roasting is usually more than 20, deep roasting is more than 30, regular roasting is 40-55, and light roasting is above 55.

The degree or depth of roasting can significantly affect the flavor characteristics of coffee, just like how coffee is roasted in a given manner: fast at high temperature, slow at low temperature, and so on. Light baking may taste bread, wood, or grain; too deep barbecue is charred and thinned. But apart from these extremes, no baking degree is necessarily better than the other. Baking preferences vary widely, influenced by tradition, brewing style (coffee used for drip brewing is usually lighter than coffee used for espresso or pressure brewing) and drinking style (people who drink milk coffee usually prefer deeper roasting to lighter roasting).

By using a specially improved spectrophotometer commonly known as Agtron, the baking degree can be measured with a certain precision. We use the M-Basic or "Gourmet" Agtron scale, and for each coffee evaluation, we provide readings of the whole coffee bean before grinding (the number in front of the slash) and the same coffee bean after grinding (the number after the slash). For example, a reading of 55 stroke 68 means that the external whole bean M-Basic reading of coffee is 55 and the grinding reading is 68. Agtron readings range from the lightest about 70 whole beans and 95 ground beans to 25 whole beans and 30 ground coffee beans (very black; basically charred, although some coffee drinkers like this style). Most of the coffee we comment on in coffee reviews is close to the middle of the proportion, with the deepest whole beans around 45 and the shallowest around 60. According to the Agtron readings, we also insert general descriptive terms for baking colors-light, medium, medium dark, dark, etc. -each coffee is reviewed according to the terminology developed by the Fine Coffee Association of America.

Here is a detailed description of the color value of coffee roasting:

Roast

Agtron

Characteristics

Light

> 70

Light brown to cinnamon

The body color is lighter, sometimes the aroma is lighter and has the smell of tea.

Bean noodles are oil-free

Medium-Light

61-70

Medium light brown

Bright, sweet acidity, the difference between green coffee is clear

Keep the surface of coffee beans dry

Medium

51-60

Medium brown

The acidity is balanced, the wine is fuller, and the difference between green coffee is still obvious.

General dried bean surface

Medium-Dark

41-50

A rich brown

Oil droplets appear on the surface of beans

The fruit turns chocolate, with a hint of roasted bitterness.

The acidity weakens and sometimes the wine is heavier.

Dark

35-40

Dark brown / black

Oil stains to the shiny surface

Bittersweet, scorched wood tastes outstanding.

Soft acidity

Very Dark

25-34

The black surface is covered with gloss.

Bitter / bitter sweet tones dominate

The body becomes thinner and the difference between green coffee is completely muted.

Extreme-Dark

< 25

A black, glossy surface

Burning bitterness dominates