Why Did My Coffee Machine Explode? Essential Tips for Using Espresso Machines and Replacing Gaskets

With the growing demand for coffee, many friends have purchased a coffee machine for home use, allowing them to brew a cup of coffee anytime to satisfy their cravings~

But recently, many friends have reported to FrontStreet Coffee that they occasionally experience "portafilter explosion" during use, where the portafilter "ejects from the chamber" as if blown out by pressure during extraction or when being removed, creating a mess of coffee grounds all over the table.

Actually, FrontStreet Coffee shared this phenomenon last year. The causes can be mainly divided into three categories! First is improper human operation, second is component wear and tear of the coffee machine itself, and third is quality issues with the coffee machine. But regardless of the cause, the occurrence of "portafilter explosion" is never a good thing. Not only does it create a mess and increase cleaning work, but it also poses certain safety risks. So today, FrontStreet Coffee will share in detail the causes of "portafilter explosion" and their corresponding solutions.

1. Portafilter Not Securely Locked

This is a situation easily triggered by many friends who are new to coffee machines! Because they're worried about using too much force and breaking the coffee machine, they stop locking as soon as they feel some resistance in the clasp.

This situation often leads to the coffee machine ejecting the portafilter during extraction! Because it's not securely locked, the portafilter has a larger range of movement, making it easily blown out of the brew head by the applied pressure during extraction, scattering coffee grounds everywhere. Therefore, before we start extraction, we must ensure the portafilter is firmly locked onto the brew head to prevent "portafilter explosion." Using a little extra force is fine because coffee machines aren't that easily damaged.

2. Aging Components

Besides improper operation that prevents secure locking, aging components can also lead to this situation. The most common among these is the gasket that serves as a seal (which is actually the main culprit).

A gasket is installed in the coffee machine's brew head, and as FrontStreet Coffee mentioned, its main function is sealing. However, it's also an important component for securing the portafilter to the brew head. When the gasket ages and hardens, the overall sealing performance decreases, leading to water leakage during extraction. At the same time, securing the portafilter becomes more difficult, requiring twisting to areas where the gasket damage is less severe. If not securely locked, as mentioned earlier, the coffee machine can easily blow out the portafilter. Therefore, FrontStreet Coffee suggests that when you notice frequent water leakage during extraction or when the portafilter needs to be locked deeper to secure it, it's best to purchase a brand new gasket for replacement. This not only makes extraction more stable but also reduces the probability of the portafilter blowing out.

Generally, a gasket's lifespan is about one year, depending on the frequency of coffee machine use. They can be purchased from various online channels, and specific replacement methods will be provided by the seller upon purchase, so FrontStreet Coffee won't elaborate too much here~ Besides the gasket, wear on the coffee machine brew head's clasp and the portafilter itself can also lead to insecure locking, but this probability is relatively small~

3. Insufficient Pressure Relief

Basically, every semi-automatic machine comes with an over-pressure relief valve. After we complete coffee extraction or when the extraction pressure reaches a certain peak, the relief valve will activate, releasing pressure by removing hot water.

Pressure relief requires a certain amount of time. Although not long, if we remove the portafilter before the coffee machine has completed pressure relief, "portafilter explosion" can easily occur. Some home coffee machines of lower quality often require longer pressure relief times when stopping extraction. These machines that require long pressure relief times are more likely to cause "portafilter explosion." When pressure relief is not timely and pressure is too high for the portafilter to withstand, the portafilter will be blown out by the pressure! This situation usually occurs when grinding is too fine, the coffee puck resistance is too high, or when using a blind basket for prolonged machine cleaning. Therefore, FrontStreet Coffee suggests paying attention to two aspects here! First, don't rush to remove the portafilter immediately after extraction ends. When you see hot water being discharged from the outlet, then begin to remove the portafilter.

Second, don't perform high-pressure extraction for extended periods. When the coffee puck resistance is too high and no liquid comes out after prolonged extraction, it's best to stop extraction, remove the portafilter, adjust the grind setting, and then restart extraction. The same applies when using a blind basket for machine cleaning - short sessions multiple times, preferably not exceeding 20 seconds per session~

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Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473