If you have done any research into espresso making you may well have seen people talking about pressurized and non-pressurized portafilter baskets.
Here I’m going to explain the differences between pressurized and non-pressurized portafilter baskets.
I’m also going to look at what type of brewing scenario each basket type is best suited for.
But first…
A Table Summarizing This Article
| Basket type | Also called | Description | When you should use it? |
| Pressurized portafilter basket | Dual wall portafilter basket. | Forces your espresso through one tiny hole which slows down brewing | When brewing with pre-ground coffee. When brewing with coffee ground in a blade grinder. |
| Non-pressurized portafilter basket | Single wall portafilter basket. | Has hundreds of tiny holes that your espresso can run through during brewing. This gives you more freedom to experiment with brewing time | When brewing with coffee that has been freshly ground in a burr grinder. |
What is the Difference Between Pressurized and Non-Pressurized Portafilter baskets?
The difference between pressurized and non-pressurized portafilters is that pressurized portafilters force your espresso through one tiny hole during brewing, whereas non-pressurized portafilters have hundreds of tiny holes that your coffee can run through when brewing.
You can easily tell whether a portafilter basket is pressurized or not by turning it upside down and looking at how many holes are on its bottom.
You can see a photo of an upside-down pressurized and non-pressurized portafilter below:
Pressurized portafilter baskets are also called “dual wall” portafilter baskets.
Non-pressurized portafilter baskets are also called “single wall” portafilter baskets.
How Do Pressurized and Non-Pressurized Baskets Affect Your Espresso Brewing?
The two baskets differ in how far they restrict the flow of water through your puck of ground coffee.
The pressurized portafilter’s single hole slows down the speed at which water can pass through your puck of coffee.
A pressurized basket, therefore, sets a minimum amount of time that your coffee beans come into direct contact with water regardless of how your coffee beans are ground and tamped.
A non-pressurized portafilter basket’s many holes mean that it does not restrict the flow of water through your coffee puck to anywhere near the same extent.
When you brew with a non-pressurized portafilter basket, the amount of direct contact time between your ground coffee and water is determined more by how your coffee is ground and tamped rather than by the basket itself.
Should I Use Pressurized or Non-Pressurized Portafilter Baskets?
Here are the circumstances where it is better to use pressurized portafilter baskets:
- When you are brewing with pre-ground coffee.
- When you are brewing coffee that has been ground in a blade grinder (rather than a burr grinder).
- If you are not confident with your tamping.
The table below shows how a pressurized portafilter basket helps you in each of the three circumstances listed above:
| Circumstance | Problem this causes | How a pressurized portafilter basket fixes this problem. |
| You are brewing with pre-ground coffee. | Your coffee is too coarse so water runs through it too quickly. This creates a sharp espresso. | The single hole in the basket creates a bottleneck so water runs through your coffee puck more slowly. |
| You are brewing with the coffee ground in a blade grinder. | Your coffee is ground unevenly so more water will flow through the coarser grounds than the finer grounds. This creates a bitter espresso. | The single hole in the basket forces the water to “sit” in the coffee bed so all grounds come into direct contact with water. |
| You are not confident with your tamping. | Your coffee puck may not be level so more water will flow through the thinner parts of the puck than the thicker parts. This creates a bitter espresso | The single hole in the basket forces the water to “sit” in the coffee bed so the whole puck comes into even contact with the water. |
You should use non-pressurized portafilter baskets if you are brewing coffee that you grind in a burr grinder.
If you brew with finely and evenly ground coffee and use a pressurized portafilter, then water will flow too slowly through the coffee bed and the resulting drink will be very over-extracted and bitter.
The puck of coffee itself provides enough resistance to the water flowing through it to achieve the correct amount of extraction for espresso.
Do Pressurized Portafilters Mean I Can Make Amazing Espresso With Pre-Ground Coffee?
Since pressurized portafilters can remedy some of the drawbacks that come with brewing espresso with pre-ground coffee, this begs the question of whether you can save money on a grinder by brewing with pre-ground coffee and a pressurized portafilter.
While a pressurized portafilter basket allows you to make decent espresso with pre-ground coffee, this still will not be as good as espresso made with freshly ground coffee and a non-pressurized portafilter.
This is for two reasons
- Pressurized portafilter baskets create a bland foam that sits upon your drink due to the additional air forced through it when the liquid coffee runs through such a tight space. This is often referred to as “fake crema” and is seen as undesirable in espresso.
- Pressurized portafilter baskets stop you from being able to fine-tune brewing time through how you grind and tamp. It forces you into a “one size fits all” approach with your brewing which puts a ceiling on espresso quality.
Therefore I’d still recommend brewing with freshly ground coffee and non-pressurized portafilter baskets if you can.
Which Espresso Machines Come With Pressurized Portafilter Baskets?
The more affordable espresso machines tend to come with pressurized portafilter baskets only.
These include:
- Delonghi’s Dedica range: For more information about this please see my Delonghi Dedica EC680M review
- Certain Gaggia machines including the Gaggia Classic and the Gaggia Carezza Deluxe. This Carezza Deluxe features in my roundup of the best Gaggia espresso machines.
Becko espresso machines. These are generally seen as the most inexpensive espresso machines on the market.
Which Espresso Machines Come with Non-Pressurised Portafilter Baskets?
Very few espresso machines come with only non-pressurized portafilters.
The majority of machines come with both types of baskets. This allows you to brew to your machine’s potential with both pre-ground and freshly ground coffee.
Espresso machines that come with both types of portafilter baskets include:
- All Breville espresso machines. You can find out more about these machines in my roundup of the best Breville espresso machines and my review of the Breville Barista Pro.
The Gaggia Classic Pro. You can find out more about this in my roundup of the best espresso machine for beginners.
Does Portafilter Basket Size Matter?
Portafilter baskets can also vary in size as well as in whether they are pressurized or not.
The baskets vary in size in two ways. They are:
- The volume of ground coffee that they can hold.
- Their diameter
I’ll quickly go through these variables in more detail.
Volume of Ground Coffee Held
Portafilter baskets vary in how much volume of coffee they hold.
This is a function of their depth multiplied by their diameter.
You get smaller portafilter baskets designed for a single espresso, and larger baskets designed for a single espresso.
Single espresso baskets hold between 7-10 grams of ground espresso, with double espresso baskets holding between 14-20 grams.
Every basket is designed with a maximum amount of ground coffee in mind, and overloading a basket can lead to an overly sharp, under-extracted espresso.
There is, however, no minimum amount of ground coffee you can use in a basket.
It’s therefore absolutely fine to brew a single espresso in a basket designed for a double espresso.
Some espresso geeks even think that brewing in a basket is “too big” for the drink you are making improves the espresso. You can see an example of someone espousing this view on the espresso subreddit below:
Diameter
Portafilters’ basket range in diameter from about 49mm to 58mm.
The basket’s diameter does not make too much difference to your brewing, however having a machine that takes the more common diameters makes it easier to find replacement parts.
54mm and 58mm are the most common diameters for portafilter baskets.
Final Thoughts
I hope that you now understand what people mean when they talk about pressurized and non-pressurized portafilters.
If you are interested in seeing what espresso machines are available, please see my list of espresso machine reviews and roundups.
