Analysis of the high-pressure extraction principle of Italian coffee machines

Espresso machines are known for their unique high-pressure extraction technology, which allows them to produce espresso. This coffee machine heats water to about 90°C and then passes it through finely ground coffee beans at a high pressure of 9 to 10 bars, a process called extraction. The high pressure quickly penetrates the fine particles of the coffee beans.

Main coffee bean types and how they perform in espresso machines

Coffee beans are mainly divided into two types: Arabica beans and Robusta beans. Arabica beans are the most common variety of coffee beans, accounting for more than 70% of global coffee production. They are usually grown in high altitude areas and have a softer taste, moderate acidity, and fruity or floral aromas. Arabica beans perform well in espresso machines and can produce espresso with a rich taste and distinct flavor layers.

Unlike Arabica beans, Robusta beans have a higher caffeine content and a stronger and somewhat bitter taste. They are mainly grown in low altitude areas and are suitable for making strong coffee drinks. In espresso machines, Robusta beans are able to produce more coffee oil, giving the coffee a stronger taste and rich crema (coffee oil foam). This bean is often used in espresso and espresso blends to enhance flavor and concentration.

In addition, some types of coffee beans are a mixture of these two beans, such as "Italian blended beans". This type of blended beans can combine the soft flavor of Arabica beans and the richness of Robusta beans to meet the needs of different tastes. When choosing suitable coffee beans, you need to make a choice based on your personal taste preferences and the performance of the espresso machine.

How to choose coffee beans for your espresso machine

When choosing coffee beans for an espresso machine, you need to consider the degree of roasting and grinding of the beans. These two factors directly affect the taste and strength of the coffee. First of all, the degree of roasting has an important impact on the flavor of the coffee beans. For espresso machines, dark roasted coffee beans are usually recommended because dark roasting can produce a strong flavor and richer coffee oils, which is especially important for making espresso.

Secondly, the grind size is another key factor. Espresso machines require finely ground coffee beans so that they can extract the best coffee flavor through high pressure. If the grind is too coarse, the coffee will not be fully extracted, which may result in a weak taste; while if the grind is too fine, it may lead to over-extraction and make the coffee bitter. Therefore, it is crucial to make sure that you use finely ground coffee beans that are specially adjusted for espresso machines.

When choosing, you can decide the roasting degree and grinding degree of the beans according to your personal taste preference. If you prefer a soft flavor, you can choose medium or dark roasted Arabica beans; if you like a strong taste, you can consider a blended bean containing Robusta beans. In short, choosing the right coffee beans and adjusting the appropriate grinding degree will help you maximize the performance of your espresso machine and make delicious espresso.

How to store coffee beans properly to maintain optimal freshness

In order to maintain the freshness and flavor of coffee beans, the correct storage method is essential. First of all, coffee beans should be stored in a sealed container to prevent air from entering. Oxygen in the air will accelerate the oxidation process of coffee beans and cause flavor loss. Therefore, choosing a well-sealed container, such as a vacuum jar or a sealed bag, is an effective way to preserve coffee beans.

In addition to avoiding air, moisture is also an important factor in preserving coffee beans. Coffee beans are easily affected by moisture in a humid environment, which affects the flavor and texture. To prevent moisture, coffee beans should be stored in a dry, cool place and avoid contact with moisture or high humidity. Do not place coffee beans in the refrigerator, as the humidity in the refrigerator may have a negative impact on the coffee beans.

FAQs on choosing an espresso machine and coffee beans

1. Why does the roasting degree of coffee beans affect the taste of coffee? The roasting degree determines the flavor characteristics of coffee beans. Deep roasted beans usually have a strong caramel and chocolate flavor, which is more suitable for making espresso; while medium roasted beans are more balanced and suitable for a variety of coffee drinks. Choosing the appropriate roasting degree can be determined according to personal taste preferences.

2. Why do espresso machines require a specific grind size? Espresso machines require finely ground coffee beans to ensure the effect of high-pressure extraction. If the coffee beans are ground too coarsely, the water will flow too fast and the flavor of the coffee cannot be fully extracted; if the grind is too fine, it may cause over-extraction and make the coffee bitter. The right grind size can ensure a balanced taste of coffee.

3. How to choose coffee beans that suit your taste? When choosing coffee beans, you can refer to the origin, variety, and roasting degree of the beans. For example, Arabica beans are suitable for people who like fruity and floral aromas, while Robusta beans are suitable for people who like strong and bitter flavors. You can try different types and blends of beans to find the one that best suits your taste.

4. How should coffee beans be stored to keep them fresh? Coffee beans should be stored in a sealed container and away from air. Storing them in a dry, cool place away from moisture and sunlight can maximize the freshness of the beans. Avoid placing coffee beans in the refrigerator, as the humidity in the refrigerator is not good for coffee beans.