Talk about coffee roasting: can coffee beans be roasted twice?

Professional barista communication, please pay attention to coffee workshop (Weixin Official Accounts cafe_style )

“啲!”The shop was pitch black. The excavation works outside the street caused the coffee shop to lose power. The most affected are the coffee beans being roasted in the furnace.

The guest saw me discharge the wheat-colored green beans from the furnace and lunged at the meter like an arrow. "Why did you release the beans to cool down? Can't we just wait for the power to be rejected before firing?"

The coffee beans are let out to cool because the beans have been soaked. Reopening the furnace as soon as possible is to avoid deformation of the cast iron drum at a temperature of up to 200 degrees Celsius under the influence of gravity at rest. After frying beans, cool the oven to room temperature and idle for at least 15 minutes.

"The beans were in the oven for more than six minutes and the temperature reached more than 170 degrees Celsius. In terms of surface color, it can be described as "cinnamon roast". However, due to insufficient heating time, the bean heart is not ripe, so drink up sour very astringent. Unripe beans are hard and may not even grind.

Like steamed fish.

"It's like steamed fish that doesn't taste good. Coffee beans should be fried in one go. The cooked outer layer becomes overcooked if it is heated after cooling. Stir-fried beans require more heat because the moisture that helps conduct heat to the heart of the beans has evaporated. By the time the heart is ripe, the noodles are charred."

This is also why there is a difference between the baking of new crop and old crop. The latter stayed in the warehouse for several months, and the original emerald coffee beans would become dull due to moisture evaporation. Fried up, the surface of beans easier to over-cooked, taste more sluggish. Real boutique cafes generally use green beans harvested less than a year ago. Packaging is also more exquisite than before; for example, the humidity control of linen bags is poor, and it is easy to be invaded by pests, so beans will be packaged in plastic film before entering bags or cartons. The best auction coffees are often vacuum packed in tinfoil bags. The moisture content of coffee beans will increase due to wet weather in recent days, so it is necessary to use more heat to achieve the same roasting curve.

"Chemically, once the complex Maillard Reaction is interrupted, it is impossible to produce the same substance even if it is reheated." This is how I explain to my guests.

A customer who often brings coffee back from the United States says,"Rumor has it that George Howell of Terroir Coffee, one of the promoters of fine coffee, freezes raw beans and then stir-fries them?" I once discussed a similar legend with a fan of fried beans from Atlanta.

Raw beans frozen and fried?

"Coffee beans are like vegetables and fruits. It can be kept fresh temporarily in the refrigerator, but can the freezing of moisture in the beans promote the process of frying beans? Our conclusion is that no chef will defrost the steak before frying it!"