The espresso machine is a high-end coffee machine that usually uses a high pressure of 15bar to 19bar for extraction. If the pressure of the espresso machine is insufficient, it will not be able to extract perfect coffee quality, often resulting in a bitter or tasteless coffee. The following are common reasons for insufficient pressure in espresso machines:

1. The fineness of the coffee powder is not enough: If the fineness of the coffee powder is not enough, the water flow will be too fast and insufficient pressure will be formed. The thickness of the coffee powder needs to be adjusted according to the model of the machine and personal taste. Coffee powder that is too fine or too coarse may cause insufficient pressure.

2. The density and shape of the filter: The density and shape of the filter have a great impact on the pressure of the espresso machine. If the pore size of the filter is too small or irregular, it will block the flow of water and cause insufficient pressure. When purchasing a filter, you need to pay attention to the quality and specifications to ensure that it can fit your coffee machine.

3. The sealing of the coffee pot: The sealing of the coffee pot is also an important factor affecting the pressure. If the coffee pot doesn't seal well enough, water vapor can leak out, causing a lack of pressure. When using the coffee machine, make sure the lid of the coffee pot is installed and sealed well.

4. Incomplete cleaning of the coffee machine: Incomplete cleaning of the coffee machine is one of the important reasons for insufficient pressure. Residues inside the machine can clog the water pipes or filters, impeding the flow of water and causing insufficient pressure. Therefore, when using the coffee machine, you need to pay attention to cleaning the residue inside the machine to ensure its normal operation.

5. Water quality issues: The coffee machine needs to use pure water, otherwise impurities in the water will clog the coffee pot and filter, hinder the flow of water, and cause insufficient pressure. You need to ensure that the water quality is good before using the coffee machine, and clean the water tank in the coffee machine regularly.

In short, the above points are common causes of insufficient pressure in espresso machines. Therefore, you need to pay attention to these factors when using the coffee machine to ensure its normal operation and extraction of perfect coffee quality.