What is a filter basket? A filter basket is a small perforated container that holds coffee grounds and sits inside a portafilter. The tiny holes in the basket act as a filter for the coffee as it drips through.
There are three types of espresso portafilter baskets: pressurized baskets, non-pressurized baskets, and blind baskets.
What are the key differences between pressurized and non-pressurized baskets?
|Pressurized Portafilter Basket||Nonpressurized Portafilter Basket|
|Has two walls. The inner wall has multiple holes and the external wall has a single tiny hole||Has one wall with multiple holes|
|Builds high backpressure inside the basket for a consistent extraction||Uses the coffee puck to build backpressure for coffee extraction|
|Makes up for inconsistencies in the coffee puck with pressure||Requires a perfect coffee puck to build consistent pressure|
|Beginner-friendly||Requires proper technique to pull good coffee|
Pressurized Filter Baskets
Pressurized or dual-walled filter baskets have two walls: the inner wall has numerous tiny holes whereas the outer wall has one tiny hole. This creates resistance to the flow of water so that water has more time of contact with the coffee puck to make espresso.
The build-up of pressure causes coffee to flow through the tiny hole under pressure.
Pressurized portafilter baskets are common in cheaper entry-level espresso machines that can not generate enough pressure. These machines rely on the pressurized filter baskets to compensate for the inadequate pressure to extract an espresso shot.
Pressurized filter baskets aid in masking puck inconsistencies when pulling an espresso because the baskets build enough resistance to make up for poor grind size, and poor dosing and tamping to extract a consistent espresso.
Double-walled baskets are also useful when using coffee beans and grounds that are past their prime.
We recommend pairing pressurized filter baskets with spouted portafilters because the spouted filters break the flow of the espresso and minimize splashing.
When To Use a Pressurized Filter Basket
We recommend using pressurized portafilter baskets in the case of the following scenarios:
- When using pre-ground coffee such that you have no control over the size of the grounds
- When using a bad grinder or coarse grounds that can not build sufficient pressure for optimum extraction
- When using espresso machines that are not able to build enough pressure to pull an espresso
- For beginners who are still learning and experimenting with grind size and tamping technique.
The downside of using a double-walled filter basket is that it will limit you from detecting coffee puck inconsistencies and therefore delaying your improvement process.
Non-pressurized/Regular Filter Baskets
Non-pressurized (Single-walled) portafilter baskets have a single wall with multiple tiny holes through which coffee flows. Regular baskets use the coffee puck to build back pressure when extracting espresso.
Therefore, regular baskets require a perfect grind size and a consistent puck to pull a good espresso.
Single-walled baskets are ideal for freshly ground coffee and espresso coffee makers that generate enough pressure for espresso extraction. Also, ensure that your grinder is capable of grinding an espresso grind size when using regular baskets.
You can use non-pressurized baskets with both spouted and naked portafilters.
Blind baskets have no holes and are useful when performing a backflush on the group head of your espresso machine to clean the mesh screen.
Portafilter Basket Sizes
The size of portafilter baskets varies in diameter and depth. The most common, and often the standard, size for commercial filter baskets is 58 mm in diameter.
51 mm, 53 mm, and 57 mm espresso basket sizes are more common with home espresso machines. Still, you can find home espresso makers that use 58 mm portafilters and baskets such as the calphalon espresso machine.
The smaller baskets are deeper than the wider baskets.
The jury is divided as to the best size of portafilters. Most espresso experts prefer 58 mm portafilters. However, some people opine that the smaller portafilters that are deeper are easier to level tamp with a deep tamper and they are also more forgiving when channeling occurs.
The size of a filter basket depends on the diameter of the portafilter and, most importantly, the diameter group head of the espresso maker.
The type of espresso machine dictates the size of portafilters, filter baskets, and the tamper that you use.
Are Portafilter Baskets Interchangeable?
Yes, you can swap portafilter baskets so long as they are the same size as the portafilter. This means that you can replace the filter baskets of an espresso maker with similar-sized baskets of a different espresso maker.
However, unlike the baskets, portafilters are not interchangeable between different espresso machine brands and sometimes even within the same brand as the thickness of the rims and ears is different. The positioning of the ears on the portafilter is also different among the portafilters.
Ridged vs Ridgeless Filter Basket
A ridged portafilter basket has a groove that runs around the basket and snugs on the portafilter. The ridge prevents the basket from falling off when tapping coffee pucks from the portafilter.
The main drawback to ridged baskets is that used grounds tend to stick in the ridge and you need to rinse with water or use a nylon brush to clean the ridges every time you make espresso.
Ridgeless baskets have no groove and provide a cleaner finish when removing pucks from the basket. However, ridgeless baskets tend to fall easily from the basket when knocking the old pucks out.
There is a place for both pressurized and non-pressurized filter baskets in espresso machines. Pressurized baskets are ideal when an espresso machine can generate enough pressure or there are inconsistencies in the ground coffee.
Pressurized baskets are also beginner-friendly when experimenting with different grind sizes and distribution and tamping techniques. However, they can delay your progress if you stick to them.
See this post about espresso distribution techniques.
The main drawback to pressurized filter baskets is that they yield a bloated crema that tends to dissipate pretty fast. Pressurized baskets should be used in spouted portafilters to break the flow of the coffee and minimize spraying.
Non-pressurized portafilter baskets are single-walled and they produce the best crema when the espresso is pulled correctly. However, they are less forgiving when the puck is inconsistent or the espresso maker can not generate sufficient pressure.
Although the spent coffee pucks fall off much easier from a ridgeless portafilter basket than a ridged basket, ridgeless baskets fall easily when knocking the pucks out.