How to choose the coffee beans
First, use fresh coffee beans.Pay attention to the color of the beans and consistency the size at the time of purchase. The good coffee beans are bright and shiny, with a strong aroma without mixing odor. No matter what type of coffee beans, freshness is an important factor influencing coffee quality. When shopping, grab one or two coffee beans and chew them in your mouth. Crisp sound (indicating that the coffee is not damp) and the scent remaining in month is the top grade. And it is better to squeeze it by hand and feel if it is solid. Do not Buy crispy coffee. If the coffee beans have lost their aroma or metamorphic smelled. It means that the coffee beans are no longer fresh and are not suitable for purchase.
Freshly fried coffee beans are not suitable for immediate consumption and should be stored for one week in order to completely release the gas inside the beans.
The beauty of coffee is the aroma; the aroma begins to drain at the moment of baking. No matter how expensive the coffee beans are, if they are not fresh, the taste will be greatly reduced. In the book Espresso coffee: the science of quality, Andrea Illy, the current head of the Italian coffee illy, has a detailed description of aroma relase and the impact of different packaging to coffee beans quality. Every kilogram of coffee beans, in an unsaturated environment, will emit 6 to 10 liters of carbon dioxide, equivalent to 1% to 1.2% of the total weight of the beans. About 35 percentage of coffee, aroma is discharged in the first 3 days after baking. And carbon dioxide is removed along with equal amounts of volatile aromatics. That is to say, there is some flavor, which will dissipate after the coffee beans are fried for the first 3 days. The author further mentioned that not fresh beans not only "lose" the good taste, but also create a bad taste. The compounds in the beans are affected by oxidation and the taste becomes negative. Therefore, the coffee on the shelves of the supermarket is generally slightly oily. Because it usually take a few months from baking and importing to foreign shelves. The "appreciation period" (note: not a shelf life date) has already passed.
In general, the best drinking period for coffee is one week after the baking when the coffee beans are the freshest and the Aroma taste is the best.
In addition, the purity of coffee beans is another consideration. How expert chooses coffee? Not mainly the size of the seeds. Instead, grab a single piece of coffee (Regional Coffee), about dozens of beans, and check each Whether the color of a single bean is the same, whether the bean size and shape are similar, so as to avoid the inferior product that is mixed by different beans. However, if it is Blended Coffee, the difference in size and color is a normal phenomenon. In addition, heavy fire and medium-deep roasting method will cause the coffee beans to produce oil. If the light-roasted beans are oily, it means that it has deteriorated, not only the mellowness is lowered, but also the astringency and sourness will appear. In short, you should pay attention to its freshness, aroma and taste when purchasing coffee, and the ideal purchase quantity is consumption for half a month.