Coffee beans knowledge and freshness and packaging storage related knowledge

Green coffee beans (i.e., unroasted) do not spoil for years, but once they enter the roasting process, the aroma awakens and they begin to age day by day. Roasted coffee beans will lose their flavor in three to four days if they are not properly preserved; if they are properly stored, they may be allowed to extend the taste period by three or four months. Fresh coffee beans are easy to bubble out of the mellow nectar, tasteless coffee beans even gods are difficult.

Raw coffee beans do not smell good, there is a smell of soil, but after roasting, hundreds or thousands of aromatic substances, mostly acidic components, such as citric acid, malic acid, tannic acid, etc., so coffee is acidic beverage, PH value about 4.7-5.2, at present the laboratory can only distinguish the ripe beans in seven or eight hundred aromatic components, which is the human diet, the most aromatic one, more than vanilla or wine. Scientists say there are at least a thousand more components of coffee beans that have yet to be isolated.

Moisture, oxygen and heat are the enemies of coffee beans

Baked coffee beans, emitting charming aroma, but fragrance at the same time, charm rapid loss. Once coffee beans are baked, they are exposed to oxygen, moisture, strong light and high temperature, which is the biggest killer of coffee aroma. This is especially important for coffee shops, because the grinder is placed next to the espresso machine, and the moisture and heat of the milk foam are eroding the coffee beans every minute. Worse, the coffee beans are ground into a fine powder, which is more fragile and easy to absorb moisture or be oxidized by the air. In order to ensure the quality, the amount of grinding beans should not be too much each time, the most ideal situation is that the guests order a cup of grinding powder, but the coffee house guests flow is large, not durable, order a cup of grinding in the implementation of difficulties, but experienced, responsible bar master, will see the number of guests, control the grinder, the amount of grinding enough to turn off, so as not to grind beans machine keep running, increase the temperature will make coffee sour, adverse coffee powder preservation, this action is very important.

Espresso machines are among the most sensitive to coffee freshness. Do an experiment, grind coffee powder immediately make a cup of espresso, you will find that the coffee flow out of the sticky thick, Crema(Crema) is very thick, and the color is golden yellow, if the coffee powder placed for more than 15 minutes, even if the lid of the grinder is very tight, the espresso will become thin as water, lost the sticky feeling, Crema is also thin, and the color is red, the flow rate is also relatively fast, which means that the coffee powder is not fresh.

Use small pots more often

How to buy coffee beans, how to keep them fresh to extend the taste period? The basic principle is to find a way to block oxygen, moisture, high temperature and sunlight, and store at room temperature, if you want to put in the refrigerator, be sure to use airtight cans, so as not to inhale impurities. It may be divided into several small jars, clean small glass jars are very good 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, open and close every day, it will taste in a few days, so the smaller the pot, the better, and the amount used up in two or three days is appropriate. It is not recommended to use a vacuum can, because the action of pumping will extract the aroma of coffee. Consumers had better buy a bean grinder and grind as much as they drink. Try not to grind beans in cafes, because after grinding into powder, it is easier to lose flavor. Moreover, it is difficult for shop assistants to grasp the thickness of each consumer's preference, which affects the flavor to the extreme. Moreover, the fragrance of grinding beans can be kept at home.

Buy expanded coffee

Before buying cooked coffee beans, pay attention to the display and packaging methods. If coffee beans are exposed to large cabinets or large cans, it is best not to purchase them, because they are in frequent contact with the air and most of them are not fresh. It is best to buy coffee with one-way exhaust valve packaging, which is currently recognized as the best way to preserve the effect, the carbon dioxide produced by cooked beans can be discharged from the valve, while the outside air can not enter.

Buy one-way exhaust valve packaging coffee also has knowledge, it is best to choose the drum, will expand the best, because coffee will release a lot of carbon dioxide (CO2) within a month after the discharge, once the discharge is completed, the flavor begins to taste, the coffee bag is flat, squeeze out the coffee flavor, the coffee in the bag is not fresh.

In principle, light baked beans taste longer, heavy baked beans shorter. Coffee beans packed with one-way exhaust valve, within four months from the date of discharge, brewed in drip filter or French filter pot, the flavor is not too bad. However, if the reroasted beans are used to make espresso coffee, the freshness is more critical. Even if they are packaged with one-way exhaust valves, they can only be kept fresh for one month at most. Therefore, roasting degree, brewing method and taste period have some relationship, in short, espresso is the most picky about freshness, shelf life of up to one month. Follicle or French press is less sensitive, from the date of release within four months and one-way exhaust valve packaging coffee beans, are considered fresh, but for espresso machines, has been stale beans.

Imported brand name beans are mostly not fresh

Although the one-way exhaust valve can extend the coffee taste period, but roasted coffee, no matter how preserved, can not stop the natural decline process, there are many so-called American or European brand coffee, claiming that the one-way exhaust valve can be kept fresh for more than six months, or even a year, this is self-deception theory, aimed at reducing wear and tear. Consumers had better buy coffee beans from domestic factories, fresh and more secure, of course, their own fried beans or roasted coffee at home, fresh and most secure, why spend a lot of money, buy imported famous brand of tasteless beans.

Don't buy coffee bricks, although this packaging method saves space, it can't make good coffee, because to press it into a brick shape, you must first grind the coffee into powder, and then go through the artificial taste process, so that carbon dioxide is released completely, in order to package it into square coffee bricks.