To brew a delicious single-origin coffee at home, good beans alone are not enough—the coarseness of the grind, the water temperature, and the extraction method all directly affect the final flavor. This article starts with the principles of coffee grinding, sorts out the differences among the three grinding methods—grinding, pulverizing, and mortar grinding—and systematically introduces the four major categories of brewing techniques: decoction, pressure, gravity, and infusion. It covers the key operating points of classic equipment such as Turkish coffee, the moka pot, the French press, and the vacuum coffee maker, helping coffee enthusiasts find a brewing method that suits them.

In 1905, Palestine used the "mortar grinding" method to make coffee

The final quality of a cup of coffee depends largely on whether the coffee grounds are ground appropriately. The coarseness of the grind must match the brewing method used—this is the core step in whether the essence and flavor of the coffee beans can be fully released. If the coffee grounds are in contact with hot water for a longer time, relatively coarse particles should be chosen. Conversely, if the grounds are ground finer than the brewing method requires, the finished cup often tastes bitter and astringent, with a sense of being "overbrewed." Going to the other extreme—grinding too coarsely—makes the coffee taste thin as water, lacking complexity.

Once ground, coffee's surface area increases greatly, making it highly susceptible to oxidation and deterioration on contact with air. As everyone's demands for coffee quality continue to rise, more and more people now choose to grind beans at home, grinding fresh and brewing fresh. Household equipment specifically designed for grinding coffee beans is also now very abundant on the market.

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

Grinding: The principle is to crush and pulverize coffee beans through two rotating components, which may be disc-shaped or conical. Conical burr grinders operate relatively quietly and are less likely to jam or clog. Coffee grounds produced by grinding are relatively uniform in particle size, and flavor release during brewing is more consistent. The design of conical burrs lowers the demand for rotational speed, usually no more than five hundred revolutions per minute. The slower the speed, the less heat generated by friction, and the less easily the coffee's aroma is lost. By adjusting grinding parameters, conical burr grinders can adapt to various types of coffee-making needs, and better-quality models can even grind the ultra-fine powder required for Turkish coffee. Flat burr grinders generally run at higher speeds and generate more heat; however, they cover a wide range of functions and are affordable, enough to handle most home coffee preparation.

Pulverizing: Most modern machines actually chop coffee beans at high speed, from twenty thousand to thirty thousand revolutions per minute (some people simply use a blender). This type of blade grinder has relatively long-lasting consumable parts; however, heat builds up during pulverizing, and the resulting coffee particles vary greatly in size, making it difficult to extract a high-quality drink. In principle, this type of grinder is only suitable for use with drip coffee makers. The fine dust they produce will clog the filters of espresso machines and French presses.

Mortar grinding: If you really have no good grinding equipment on hand, then you can only take out a pestle and a mortar and, like the "Jade Rabbit pounding medicine," slowly enjoy the pleasure of manual labor.

Brewing

No matter which kind of coffee it is, it is essentially the product of ground coffee combined with hot water; after completion, the coffee grounds are removed. How fine the coffee needs to be ground depends on the brewing method chosen. Proper water temperature is crucial. The choice of water temperature is related to the brewing equipment, the coffee bean variety, and the degree of roasting: if the water temperature is too low, the flavors in the coffee beans cannot be fully extracted; if the water temperature is too high, over-extraction occurs, the taste deteriorates, and it often becomes bitter. If the water passes through the coffee grounds only once, the finished product will mainly contain easily soluble substances (including caffeine). If the water circulates through the coffee grounds multiple times (as in common percolators), those substances in the coffee beans that do not dissolve easily will also enter the finished product, making it taste bitter; for this reason, this method is not favored by enthusiasts. The common ratio of coffee grounds to water in Western countries is 15–30 milliliters of coffee grounds (one to two tablespoons): 300 milliliters of water (six ounces). Coffee enthusiasts often take the upper limit of this ratio. Please note that appropriate adjustments should be made according to the coarseness of the coffee grounds. Continued heating will destroy the flavor of brewed coffee, and degradation also occurs at room temperature. Therefore, keeping brewed coffee warm often turns out to be a mistake. However, in an oxygen-free environment, coffee can be stored at room temperature for a long time. That is why you can see sealed packages of coffee on store shelves.

According to the way water and coffee grounds come into contact, coffee brewing is classified into four types: "decoction," "pressure," "gravity," and "infusion."

Decoction method

Do not be misled by the name. Do not boil the coffee (at least not for too long), otherwise it will be too bitter.

The simplest method is to put coffee grounds in a cup, add hot water, and let it cool while the coffee grounds sink to the bottom. This is an old method, and it is still used in some places in Indonesia today. Be careful not to swallow the coffee grounds 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 recipe, still used in the Middle East, North Africa, East Africa, Turkey, Greece, and the Balkan region. Ultra-fine coffee grounds are boiled with water in a small-mouthed vessel, generally seasoned with sugar and cardamom. The strong coffee served in the cup has foam on top and a layer of settled powder below.

"Cowboy coffee" is made by putting coffee grounds and water directly into a pot, boiling it, and drinking it. The name suggests a makeshift measure under rough conditions; however, some people prefer it. In Finland and Sweden, which have the highest per capita coffee consumption, this is their traditional brewing method.

Pressure method

Espresso is made by forcing hot water at 80–96 degrees Celsius through a compacted puck of coffee grounds at a pressure of 8–9 atmospheres, and usually a single serving is only 30 milliliters. It is one of the strongest among common coffees, with a unique aroma and a layer of crema floating on the surface. It can be drunk on its own; it can also be further made into many other drinks. Because brewing is quick, it is highly concentrated, and its caffeine content is low, this method is used in many chain coffee shops and flavored coffee drinks.

The moka pot, also called the "Italian coffee maker," is a three-layer stovetop device. After the boiling water in the bottom chamber is heated, steam pressure pushes it through the coffee grounds in the middle layer and into the upper chamber. The resulting coffee concentration can be compared with espresso, except that it has no floating oils. However, if a pressure-reducing gasket is installed at the coffee outlet, golden crema can be extracted. The structure of the moka pot and the semi-automatic espresso machine is the same, but the way the water exits is reversed. After about 30–40 cc of coffee has flowed out, remove the pot from the heat source as quickly as possible, then wipe the bottom of the pot with a cold towel.

Gravity method

American coffee, or the filter paper method, is made by placing coffee grounds on filter paper or a metal filter and pouring hot water from top to bottom. The strength of the coffee depends on the water ratio and the coarseness of the grounds, but it is generally lower than that of espresso.

Electric percolators were widespread in the United States before the 1970s. Unlike the moka pot mentioned above: hot water boils up into the top chamber, then passes downward through the coffee grounds and returns to the heating chamber; this cycle repeats several times. It is precisely because in this method the hot water passes through the coffee grounds many times that this kind of coffee tastes poor.

Infusion method

The French press is a tall, slender glass cylinder equipped with a plunger with a filter. Hot water and coffee grounds steep in the cylinder for four to seven minutes, then the plunger filter presses the coffee grounds to the bottom, and the coffee on top can be poured out and drunk. This "full immersion method" is considered by many experts to be the ideal home method for brewing coffee.

Coffee bags are portable packaging for travel and are rarely seen at ordinary times.

Malaysians use cloth bags filled with coffee grounds, immerse them in hot water, and then take the cloth bag out of the hot water. This kind of bag follows the same principle as using filter paper. It is more suitable for the strong local coffee, and the coffee in the bag can be reused.

The vacuum coffee maker (Syphon) is formed by connecting a heating vessel and a funnel-shaped vessel. The connecting part is a filter, on which the coffee grounds are placed. After the water in the heating vessel boils, it rises into the funnel-shaped vessel and mixes with the coffee grounds; at this point the heat source is removed, and the partial vacuum formed as the heating vessel cools draws the coffee from the funnel-shaped vessel back down through the filter to the bottom.

No matter which method you choose, brands that focus on quality, like Front Street Coffee, will advise: mastering the grind size and the coffee-to-water ratio is the key to consistent results.

The above content is compiled by CoffeeHunters, a coffee news website.