Will the flavor and taste of coffee beans become better after blending?

Generally, roasting is divided into shallow, medium and deep degrees, and the baking time varies depending on the type of coffee required. The light roasted coffee beans are light and sour, the intermediate roasting is sour and bitter, and the deep roasting color is rich and bitter. The lighter the roasting degree is, the stronger the sour taste of the coffee bean is, the deeper the baking degree is, the sour taste is gradually lost, and the bitterness is heavier. Professional baking methods are usually divided into the following eight stages: very shallow baking (Light Roast), shallow baking (Cinnamon Roast), micro baking (Medium Roast), medium baking (High Roast), medium and deep baking (Cicty Roast), deep baking (Full-City Roast), very deep baking (French Roast) and very deep baking (Italian Roast). Deep baking, also known as "Italian baking", is mainly popular in Latin countries and is considered to be the most suitable for Espresso. The color of the very deep-roasted coffee beans is black, and the oil has infiltrated to the surface, so it has a bitter taste of carbon ash, and the mellowness is significantly reduced.

For some strict baking techniques, roasted coffee used in Espresso should also be fresh, so coffee roasted within four days is required. But I'm afraid this rule only applies to gluttons who bake on their own small machines. Big coffee factories have a variety of patented technologies to ensure the sealed preservation of roasted coffee beans, the more famous of which is Illy's inert gas preservation method, which has been patented since its inception, which removes the air from the container and pours it into the pressurized inert gas. The observation under the electron microscope can confirm that coffee oil is scattered sporadically in the coffee cell tissue, and after pressure, these oils will be concentrated around the cell wall, wrapping some fragrant and highly volatile chemicals in the cells, thus isolating air contact and avoiding oxidation. The technology is believed to keep the flavor and freshness of roasted coffee beans intact for up to three years, as opposed to the "blending technology school", which believes that the taste of coffee depends 80% on roasting. Regardless of the percentage data, whether you are particular about the degree of "roasting" and whether you bake it yourself, this has indeed become an important indicator to verify the identity of a coffee glutton. "roasting" refers to roasting the raw coffee beans with a special machine to make the coffee beans show a unique brown color, aroma and taste. The key point is to "stir-fry" the inside and outside of the beans evenly without being overburnt. A series of chemical changes occur during baking: moisture decreases from 10% to 1%, fat from 12% to 16%, sugar from 10% to 2%, chlorogenic acid from 7% to 4% to 5%, and nitride from 12% to 14%. The physical change is: water loss, weight reduction of 10% to 15%, volume increase of 60%.