Guide · Baskets and portafilters
Why won't my portafilter lock in?
Too much coffee, a puck screen, a different basket or a portafilter made for another machine. How to find the cause without forcing the handle.
Short answer
Start with what changed. If a portafilter that used to lock now will not, something is usually taking up room above the basket: more coffee, a puck screen or a taller basket. If a new portafilter will not lock, it was probably made for a different group, because diameter alone does not decide fit; the locking ears do. Never force the handle.
Start with what changed
| What changed | Likely cause | What to try |
|---|---|---|
| You raised the dose | Too little headspace | Lower the dose and stay inside the basket's range |
| You added a puck screen | The screen adds height above the puck | Lower the dose slightly or use a thinner screen |
| You swapped the basket | The new basket sits or fills differently | Check it seats fully; dose to its range |
| You bought a new or bottomless portafilter | Its ears do not match your group | Use one listed for your exact model |
| Nothing obvious | Grounds on the gasket, or wear | Clean the group; check your manual |
Too much coffee
The basket has to leave some room between the puck and the shower screen. Fill it too high and the puck meets the screen before the handle reaches its locked position.
Every basket is made for a dose range, and the range depends on its height. IMS lists its 24.5 mm B70 basket for 16 to 18 g of dark roast and up to 20 to 22.5 g of light roast, and its 28.5 mm version for 20 to 26 g.[1] Its 23.5 mm Breville-size basket is listed for 14 to 20 g depending on roast.[2] Notice that IMS lists larger doses for lighter roasts in the same basket, so a dose that fits one coffee may not fit the next.
For reference, Breville gives an 18 g dose for the 54 mm Bambino and Barista Express and 22 g for the 58 mm Dual Boiler.[3][4][5]
Check headspace: dose and tamp as usual, lock the portafilter in without brewing, then take it out and look at the puck. A deep imprint of the shower screen or its center screw means there is too little room. Take off a gram and try again.
A puck screen
A puck screen sits on top of the tamped coffee, so it uses some of the same space. If your basket was already full, a screen can be the thing that stops the handle. Thickness varies: the MHW-3BOMBER screen we track is sold in 0.2 mm and 0.8 mm versions (the seller's figures). Either lower the dose slightly or choose the thinner screen.
A different basket
Baskets come in different heights and shapes. IMS alone lists its B70 family in 22.5, 24.5, 26.5 and 28.5 mm heights.[1] A basket that does not sit fully down in the portafilter raises its rim, and a raised rim can stop the handle turning. Press the basket in and check that it sits flat and level before you dose.
A portafilter made for another machine
Basket diameter and locking fit are separate things. The portafilter locks into the group head by its ears (also called lugs), and their number, thickness and angle vary between makers and even between models.
Some examples from makers' own pages:
- Breville sells two different 54 mm portafilters. Spare part SP0027237 lists the Barista Express, Express Impress, Barista Pro, Barista Touch and Touch Impress, while SP0024799 lists only the Bambino Plus and its Baratza bundle.[6][7] The original Bambino is not on that list, although Breville's own page gives it a 54 mm portafilter.[3]
- Breville's 58 mm part has its own list. SP0001817 names the Oracle Jet, Oracle Dual Boiler, Dual Boiler and Dynamic Duo, but not the Oracle Touch, whose page also says 58 mm.[8][9]
- "E61" is not universal. Profitec describes the GO 2.0 as a single boiler with a "ring brew group" and does not call it an E61, so a portafilter sold for E61 machines is not automatically a GO portafilter.[10]
- De'Longhi's 51 mm bottomless portafilter is model-specific. A US retailer lists the DLSC085 for named La Specialista and Dedica Maestro models; the Dedica EC685 and EC885 are not on that list.[11]
- Labels vary even within one brand. Gaggia gives its wooden-handle filter holder a 58 mm filter diameter, but lists its bottomless filter holder as 59 mm.[12][13]
Accessory fit can differ by model too: Normcore says its 53.3 mm dosing cup, made for 54 mm baskets, is not compatible with the Barista Express Impress or similar models.[14]
The AliExpress portafilters we track are sold as variants named by machine or by ear count, such as "51 mm, De'Longhi 3 ears" or "58 mm, E61". Those names are the seller's claims. Choose the variant that names your exact model, and keep the packaging until you have confirmed it locks.
When nothing changed
If your dose, basket and accessories are the same and the handle is suddenly harder to turn, look at the group. Brush away grounds stuck around the gasket and the shower screen, then try again with an empty basket. If it still binds, or if the handle now turns much further than it used to, check your manual's guidance on inspecting the group gasket, or ask the machine's service center.
Next
Questions
Why won't my portafilter lock after I added a puck screen?
A screen adds its own thickness above the puck. If your dose already filled the basket, there may be no room left. Lower the dose a little or choose a thinner screen; see are puck screens worth it.
Will any 58 mm bottomless portafilter fit my 58 mm machine?
No. Diameter describes the basket, not the locking ears. Profitec, for example, describes the GO 2.0's group as a ring brew group rather than an E61, so a portafilter sold for E61 machines is not automatically a match.[10]
How much coffee fits my basket?
Check the basket maker's range. IMS lists its 24.5 mm B70 basket for 16 to 18 g of dark roast and up to 20 to 22.5 g of light roast, with taller versions for larger doses.[1]
Does the Bambino use the same portafilter as the Barista Express?
Both are 54 mm, but Breville sells different spare parts: SP0027237 lists the Barista Express, Express Impress, Pro, Touch and Touch Impress, while SP0024799 lists only the Bambino Plus. Buy the part listed for your model number.[6][7]
Is it safe to force a stiff portafilter?
No. Find the cause first. The group is hot, a slip can end with a burn, and forcing the handle only hides the real problem.