Knowledge related to freshness, packaging and storage of boutique coffee

Raw coffee beans (that is, unroasted beans) will not rot for several years. Once the raw beans enter the roasting process, the aroma wakes up and they begin to age day by day. Roasted coffee beans will lose their taste in three to four days if they are not properly preserved. If they are properly stored, the taste period may be extended by three or four months. Fresh coffee beans are easy to soak into mellow jade, and off-flavor coffee beans are hard to be immortals.

Raw coffee beans smell bad and have a smelly smell, but after roasting, they produce hundreds or thousands of aromatic substances, most of which are acidic, such as citric acid, malic acid, monosodium acid, etc., so coffee is an acidic beverage with a PH value of about 4.7-5.2. At present, the laboratory can only distinguish 700 or 800 aromatic components from ripe beans, which is already the most aromatic in the human diet. More than vanilla or wine. Scientists say there are at least a thousand ingredients in coffee beans that have not yet been isolated.

Gas, oxygen and high temperature are enemies of coffee beans.

Roasted coffee beans give off a charming fragrance, but at the same time, the charm is rapidly lost. As soon as coffee beans come out of the oven, they are exposed to oxygen, hydrogen, bright light and high temperature. they are the biggest killer of coffee aromatics. we must find ways to isolate them. It is especially important for coffee shops, because the bean grinder is placed next to the espresso machine, and the high temperature of the foam erodes the coffee beans every minute. What's worse, the coffee beans are ground into fine powder and are more fragile. It is easy to absorb moisture or be oxidized by air. In order to ensure the quality, the amount of grinding beans should not be too much at a time. Ideally, guests should not grind a cup of powder when they order one cup. However, the flow of guests in the cafe is large and they cannot bear to wait for a long time, so it is difficult to order a cup and grind a cup. However, experienced and responsible bartenders will look at the number of guests, control the bean grinder, and turn it off when the grinding quantity is enough, so as not to keep the grinder running. Increasing the temperature will make the coffee sour, which is not conducive to the preservation of coffee powder. This move is very important.

Espresso machine is the most sensitive to coffee freshness among all kinds of brewing methods. Do an experiment, grind the coffee powder and immediately make a cup of espresso, you will find that the coffee is sticky and thick, Crema is very thick, and the color is golden. If the coffee powder is placed more than 15 minutes, even if the lid of the bean grinder is very tight, the espresso will become as thin as water, lose the sense of stickiness, the Crema is also thin, and the color is red, and the flow rate is relatively fast. This means that the coffee powder is not fresh.

Make more use of jars

When buying coffee beans, how to keep them fresh to prolong the taste period? The basic principle is to find ways to block oxygen, oxygen, heat and sunlight, and store them at room temperature. if you want to keep them in the refrigerator, be sure to use airtight cans to avoid inhaling smells. Might as well pack in several small jars, clean the small glass jar is very easy to use, drink one can and then open the second can, you can reduce contact with oxygen.

If the coffee beans are all packed in large cans and turned on and off every day, they will lose their taste in less than a few days, so the smaller the jar, the better. It is appropriate to use up in two or three days. The use of suction fresh-keeping jars is not recommended because the aroma of the coffee will be removed by the action of suction. Consumers had better buy a bean grinder, grind as much as they drink, and try not to grind beans in cafes, because after grinding into powder, it is easier to lose taste. In addition, it is not easy for shop assistants to grasp the thickness of each consumer's preference, affecting the flavor. And the fragrance of grinding beans can be kept at home.

Choose and buy coffee in inflated packaging

Before buying cooked coffee beans, you should pay attention to the furnishings and packaging. If the coffee beans are exposed in large cabinets or cans, it is best not to buy them, as most of them are not fresh because of frequent contact with the air. It is best to buy coffee packaged with an one-way exhaust valve, which is currently recognized as the best way to keep fresh. The carbon dioxide produced by cooked beans can be discharged from the valve, but the outside air can not enter.

One-way exhaust valve packaged coffee is also knowledgeable, it is best to choose bulging, it is better to inflate, because the coffee will release a lot of carbon dioxide (CO2) within a month, once the emission is finished, the flavor begins to stale, the coffee bag is flat, can not squeeze out the smell of coffee, the coffee in the bag is out of breath and is not fresh.

In principle, the taste period of shallow baked beans is longer, while that of re-baked beans is shorter. Coffee beans packaged by one-way exhaust valve are brewed in trickle or French filter kettle within four months from the date of baking, so that the flavor will not be too bad. However, if the re-baked beans are used to make espresso, the freshness will be more picky, and even if they are packed with an one-way exhaust valve, they can only be kept fresh for a month at most. Therefore, the degree of roasting, the way of brewing and the length of taste have something to do with it. In short, espresso is the most fastidious about freshness, with a shelf life of at most one month. Follicular or French filter kettles are less sensitive. Coffee beans packaged with an one-way exhaust valve within four months from the furnace are considered fresh, but they are already stale beans for the espresso machine.

Most of the imported famous beans are not fresh.

Although the one-way exhaust valve can prolong the coffee appreciation period, the roasted coffee, no matter how it is preserved, can never stop the natural decay process. There are many so-called American or European brand-name coffee in the shop, claiming that the one-way exhaust valve can be kept fresh for more than six months, or even a year. This is self-deception and aims to reduce consumption. Consumers had better choose and buy coffee beans from domestic factories, which are fresh and more secure. of course, if they stir-fry raw beans or roast coffee at home, fresh is the most guaranteed, so there is no need to spend a lot of money to buy stale beans with imported famous brands.

Do not buy coffee bricks, although this kind of packaging saves space, it cannot make good coffee, because in order to press the coffee into bricks, you must first grind the coffee into powder, and then go through the artificial process of flavor loss, so that the carbon dioxide can be released to make it into a square coffee brick.