Espresso Puck Exploding When Removing Portafilter (Solved!)

Is the puck in the portafilter exploding when you unlock it? This is happening because of all the pressure still in the portafilter after pulling a shot.

This phenomenon is also called a “Portafilter Sneeze” It’s a common problem with espresso machines that don’t have a pressure release valve (like a lever espresso machine) and is often more noticeable after replacing seals and rings.

How To Fix An Exploding Coffee Puck?

There are a few things you can do to avoid this puck blowout. The best solutions are to just wait a minute or two, to let the pressure subside, use a non-pressurized basket, and ensure a consistent grind size.

Let’s dive deeper into these solutions and more below.

The Puck exploded After removing the portafilter

Wait A Few Minutes

After pulling a shot, don’t be in a rush to remove the portafilter. The key is to give the pressure inside the portafilter some time to decrease naturally.

Wait for a minute or two. During this time, the air gradually finds its way through tiny gaps, easing the pressure inside the portafilter. It’s like slowly letting air out of a balloon.

Once you’ve allowed this short waiting period, it’s time to cautiously remove the portafilter. But remember, it’s all about gentle movements.

Start by turning the portafilter very slightly and gradually to the side. This helps to release the pressure slowly and avoid a sudden burst – the dreaded portafilter sneeze.

Use A Non-Pressurized Basket

The short explanation:

A non-pressurized basket helps prevent a “portafilter sneeze” because it does not trap pressure in the same way a pressurized basket does. Therefore, when the extraction process is complete, the pressure dissipates more quickly and evenly, making it safer to remove the portafilter.

The full explanation:

Pressurized baskets contain a mechanism (like a single small hole or a two-layer basket design) that creates additional pressure. This design can help with brewing consistency, especially if the grind size or tamping is not ideal.

The pressurized mechanism forces the water to exit through a single point, creating a pseudo-crema. However, this artificial pressure also means the portafilter contains residual pressure after brewing, which could cause a “sneeze” if not properly handled.

This is also one of the reasons why pressurized portafilter baskets get stuck in the group head more often.

A Pressurized Basket
A Pressurized basket

Non-pressurized baskets are the traditional style and rely entirely on the coffee grind size, amount, and tamping pressure to create the resistance necessary for brewing.

The basket has many holes, so unlike pressurized baskets that trap pressure, non-pressurized ones let water flow freely.

This means that once the machine stops the extraction process, the pressure drops immediately, significantly reducing the risk of a “portafilter sneeze” when removing the portafilter.

But there is one more reason you should use a Non-Pressurized basket:

The Grinder Makes Too Many Fines

If your grinder produces too many fine particles (also known as fines), these can block the holes in the coffee basket and cause pressure build-up.

This is common when using pressurized baskets since there is only one hole where water can flow through that can easily get blocked.

If you’re getting too many fines, consider upgrading your grinder to a model that produces a more consistent grind size.

Here are a few points to consider if you’re upgrading your grinder:

  • Type of Grinder: There are two main types of grinders, blade and burr grinders. Burr grinders are generally considered superior, as they grind coffee beans to a consistent size. Blade grinders, on the other hand, tend to produce an inconsistent grind, which may lead to uneven extraction.
  • Burr Quality: Burr grinders come in two types: flat and conical. Both can produce a consistent grind, but they do so in slightly different ways. Conical burrs tend to be used in lower-speed grinders and are less likely to clog, while flat burrs are often found in high-speed grinders and are known for their precision.
  • Grind Settings: A good grinder will allow you to adjust the grind size to cater to different brewing methods. For espresso, you’ll typically want a fine grind, but having the ability to switch to a coarser grind for other brewing methods like French press or pour-over is a nice feature to have.
  • Grind Consistency: This refers to how uniformly the grinder crushes the coffee beans. A grinder that produces a consistent grind will result in even extraction and better-tasting coffee. High-quality grinders will produce fewer fines and more consistently sized particles.
  • Cleaning and Maintenance: Coffee grinders need to be cleaned regularly to prevent the buildup of old coffee grounds, which can negatively impact the taste of your coffee. Some grinders are easier to clean than others, so look for a model that makes this process as straightforward as possible.
a good coffee puck

Release The Lever First

If you’re operating a lever machine, you can decrease pressure by cautiously lifting the lever before you unlock the portafilter, but not too much to avoid adding extra water.

A moderate lift, around halfway, should be enough to let air enter the chamber, which in turn will reduce the water pressure.

Use Coarser Grind Size

When you grind coffee beans very finely, it’s harder for the pressure to escape through the compact coffee ‘puck’ and the machine’s portafilter. But if you grind the beans more coarsely, the space between particles allows air and water to move more freely. This means there’s less pressure build-up both during and after brewing.

However, you have to consider how this affects your coffee taste. Using coarsely ground beans could lead to an extraction that’s too quick. This can make your espresso taste overly sour and unpleasant.

Personally, I’d choose a bit of a mess from an over-pressurized puck over a bitter, rushed shot of espresso.

coarse ground coffee

Use A Smaller Coffee Dose

Don’t overfill the basket, the coffee puck expands a bit when it gets wet adding to the pressure in the portafilter, if there is too much coffee in the portafilter the chance of the puck exploding on release increases.

So, make sure you use the right amount of coffee, based on your basket size and the type of drink you’re making. Usually, 18g of ground coffee is enough for a double espresso shot.

Just like the grind size, this can also have a big impact on the quality of your espresso.

Tamping The Coffee To Hard

Applying too much pressure while tamping coffee can lead to a slow extraction process, often resulting in overly bitter espresso. It can also create too much pressure within the portafilter.

Therefore, just aim to compress the coffee evenly and flatly within the portafilter, which is sufficient for a good brew.

The right temp

Open The Steam Valve

In certain coffee machines, the group head, responsible for coffee extraction, and the steam wand, used for frothing milk, are interconnected. Their pressures are often linked, meaning changes to one can influence the other.

If the pressure in the group head is too high, one remedy could be to open the steam wand. This act allows some pressure to escape, thereby decreasing the pressure within the group head.

Clean The Portafilter Before Use

Ensure the portafilter and the group head are clean, with no leftovers from the last brew.

Old coffee residue can clog the machine, causing pressure to build up. Regular cleaning of the coffee machine’s main parts, like the group head, handle, and portafilter, is key for smooth operation.

After cleaning remember to always leave the portafilter in the group head, as this prevents the gaskets from drying out.

Conclusion

Managing pressure in espresso brewing is paramount to avoid “portafilter sneezes”. Waiting a few minutes before removing the portafilter, using a non-pressurized basket, and ensuring a consistent grind size can alleviate this issue.

If you’re using a lever machine, a gentle lift can help relieve pressure. Regular cleaning of the portafilter and group head will also prevent clogging that can cause pressure build-up.

Master these tips, and you’re on your way to sneeze-free espresso brewing.

Thanks for reading!