Several brewing methods of coffee are explained in detail.

Grinding system

In 1905, Palestine adopted the method of "mortar mill" to make coffee.

The quality of the minced coffee has a very important influence on the following cooking process. The grinding method should also match the cooking method, which is the key to extracting the best flavor from coffee beans. The cooking method of coffee powder which is in contact with hot water for a long time requires thicker particles. If the coffee powder is too fine relative to the cooking method, the coffee will be too bitter, hard and "overcooked". At the other extreme, of course, the coffee powder is too thick to make the finished product tasteless.

Because of the large contact area between the powder and the air, the ground coffee powder is easy to oxidize and degrade. With the improvement of people's taste in drinking coffee, more and more people tend to grind coffee beans at home and cook them now. Now there are many household appliances specially used to grind coffee.

There are three kinds of grinding methods for coffee beans: "grinding", "grinding" and "mortar grinding".

Grinding: two rotating parts are used to squeeze and crush coffee beans. The grinding parts can be disc-shaped or conical. Conical machines are less noisy and less likely to block. The coffee powder produced by the grinding method is more uniform and the taste is more consistent when cooking. The design of the conical grinding disc reduces the required speed, which is generally less than 500 revolutions per minute. The slower the grinding speed, the less heat generated by friction, so the aroma of coffee is not easy to lose. By adjusting the grinding parameters, the cone grinder can be used for the preparation of different kinds of coffee. A better machine can grind the ultra-fine powder needed for Turkish coffee. Disc grinders generally have higher rotational speed and generate more heat, but they have a wide range of functions, economical and practical, and are suitable for the preparation of most household coffee.

Polishing: most modern machines actually cut coffee beans into pieces at a speed of 20, 000 to 30, 000 revolutions per minute (some people simply use beaters). The consumption parts of this kind of blade grinder have a longer life, but the accumulated heat in the grinding and the uneven size of the coffee chips make it difficult to extract high-quality drinks. In theory, this kind of grinder can only be used for drip coffee pots. The dust they produce can clog the filters in espresso and French press machines.

Mortar mill: if you can't find good grinding equipment, all you can do is to use a pestle and a mortar to slowly enjoy the fun of labor.

Cooking

All coffee is made from ground coffee powder and hot water; it should be cleaned after it is cooked. The thickness of the coffee powder is related to the cooking method chosen. Proper water temperature is very important. The choice of water temperature is related to cooking utensils, coffee bean species, coffee bean baking degree, the water temperature is too low, the flavor of coffee beans can not be fully extracted; water temperature is too high, excessive extraction, taste deterioration and often bitter. If the water passes through the coffee only once, the finished product will contain mainly soluble substances (including caffeine). If the water cycle passes through the coffee powder many times (like a common circulating filter), the less soluble substances in the coffee beans will also enter the finished product, causing the taste to be bitter, so this method is not favored by enthusiasts. The common ratio of coffee powder to water in Western countries is 15,30mg coffee powder (one to two tablespoons): 300ml of water (six ounces). Coffee lovers often take the upper limit of this ratio. Please pay attention to make appropriate adjustments according to the thickness of the coffee powder. Continuous heating destroys the flavor of brewed coffee, and degradation also occurs at room temperature. Therefore, it is often a failure to keep the coffee warm. However, in an anaerobic environment, coffee can be preserved for a long time at room temperature. So sealed coffee can be seen on store shelves.

Nowadays, many electric coffee pots are highly automated, and some even include the function of grinding coffee beans.

According to the contact mode between water and coffee powder, coffee cooking can be classified into five categories: "steaming method", "pressurization method", "gravity method", "leaching method" and "ice brewing method".

Soaking method

Don't be misled by the name. Don't boil the coffee (at least not for too long), or it will be too bitter.

The easiest way is to put the coffee powder in the cup and add hot water. As it cools, the coffee powder will sink to the bottom of the cup. This is an old method, and it is still used in some parts of Indonesia. Be careful not to eat the coffee at the bottom of the cup. The advantage of this method is that it is simple and the water temperature is just right.

Turkish coffee is an early prescription and is still used in the Middle East, North Africa, East Africa, Turkey, Greece and the Balkans. Ultra-fine coffee powder is boiled with water in a small container, usually seasoned with sugar and cardamom. The espresso in the cup has foam on it and a layer of silted powder underneath.

"Cowboy Coffee" is to boil the minced coffee directly in the pot and drink it. The name implies a stopgap measure under humble conditions; however, some people prefer it. This is their traditional cooking method in Finland and Sweden, where per capita consumption of coffee is the highest.

Pressure method

Espresso is made from 80 to 96 degrees Celsius hot water at a force of 8 to 9 atmospheres through compacted coffee cakes, usually only 30 milliliters per cup. It is one of the strongest of the common coffee, with a unique aroma and a touch of oil (Crema) floating on the surface. It can be drunk alone; it can also be further made into a variety of other drinks. Because of its fast brewing speed, high concentration and low caffeine content, this method is used in many chain coffee shops or seasoned coffee.

The mocha pot, also known as the Italian coffee pot, is a three-layer stove. After boiling water at the bottom, the coffee powder is pushed through the middle layer by steam pressure to enter the upper layer, and the coffee concentration obtained is comparable to that of espresso, but there is no oil slick, but if a pressure gasket is installed at the coffee spill outlet, the golden crema can be extracted. The mocha pot and the semi-automatic espresso machine have the same structure, but the way the water comes out is upside down. Remove the fire from the bottom of the pot as soon as possible after the coffee spills about 30~40cc, and then wipe it on the bottom with a cold towel.

Gravity method

American coffee espresso (commonly known as hand brewing).

Electric circulating filter in the 1970s with a different mocha pot: hot water boiled into the top, and then passed from top to bottom through the hot water several times in this method, the flavor of this coffee is more unstable.

Leaching method

The French filter Press (French press) is a tall thin glass cylinder with a piston with a filter. Soak the hot water and coffee powder in a cylinder for four to seven minutes, then press the coffee powder to the bottom by a piston filter, and the top coffee can be poured out to drink. This "complete immersion method" is considered by many experts to be an ideal household method for making coffee.

Coffee bag is a portable package for travel, which is very rare at ordinary times.

Malaysians put coffee powder in cotton pockets, soak them in hot water, and then remove the cloth bags from the hot water. This kind of pocket is the same as using filter paper. This is more suitable for strong local coffee, and the coffee in the bag can be reused.

The siphon coffee maker (Syphon) is made by connecting a heating container and a funnel container. The connecting part is a filter with coffee dust on it. After boiling in the heating container, the water goes into the funnel container and mixes with the coffee powder; at this time, the heating source is cut off, and the partial vacuum formed by the cooling of the heating container pulls the coffee back to the bottom through the filter.

Ice brewing method

Ice brewed coffee, also known as ice drop coffee, is the biggest difference from the above four, that is, instead of using hot water, ice water produced by slowly melting ice is dripped slowly through a filter containing coffee dust. So making a cup of ice-brewed coffee takes a long time and costs a lot, but it tastes great.