An espresso paper filter can go above or below the coffee puck. Top paper separates the grounds from the shower screen; bottom paper sits against the basket floor and can change how espresso flows out. Each position needs the correct disc size and its own comparison brew.
Start with fit rather than a promised flavor improvement. The disc has to lie flat without folding, without riding up the basket wall, and without eating more headspace than your machine allows. A paper cut for the top of a 58 mm basket is often too wide for the narrower floor of that same basket.
Key takeaways
- Top placement is the straightforward one: a disposable barrier above the puck, on a basket with clearance to spare.
- Bottom placement needs its own diameter check against the perforated floor, which is usually much smaller than the opening.
- Change one thing at a time. Test a placement against a no-paper baseline before you touch the grind.
Top vs bottom espresso paper filter at a glance
| Question | Filter on top | Filter on bottom |
|---|---|---|
| Where it goes | Above the tamped coffee | On the basket floor, below the coffee |
| Main practical role | Keeps loose grounds off the shower screen | Adds a layer at the puck outlet and may change flow |
| Fit check | Usable inside diameter at the puck surface, plus headspace | Actual diameter of the perforated basket floor |
| Likely recipe impact | Test before changing anything | Expect to recheck flow and grind |
| Do not use when | The portafilter gets harder to lock, or the paper wrinkles | The disc rides up the wall or has no confirmed floor size |
Short version: use a top filter when a compatible basket has the clearance and you want a disposable barrier above the puck. Try a bottom filter only when a correctly sized disc lies flat on the basket floor and you are ready to dial the shot in again.
What a top paper filter actually does
Prepare and tamp the puck first, then lay one clean disc flat on the coffee. The 58 mm espresso paper filters are specified for exactly this position, 200 white single-use discs per pack. The 58 mm figure describes the paper, not your basket. Plenty of hardware sold as 58 mm measures something else where the puck surface actually sits.
What a top paper does well is keep loose grounds off the shower screen, which makes the wipe-down after a shot shorter. What it does not do is replace group-head cleaning, fix distribution, or level a sloppy tamp. It also takes up a little room above the coffee. If the handle starts resisting on the way in, stop and recheck dose, paper diameter and clearance instead of forcing it.
The same caution applies to the reusable version. A 1.2 mm stainless puck screen is thicker and reusable, sold in 51, 53 and 58 mm, and it needs its own headspace check. Paper and steel are not interchangeable just because both sit above the puck. Our puck screen size and headspace guide covers that decision on its own terms.
Why bottom placement needs a different size check
For bottom placement, set the paper into an empty, dry basket before any coffee goes in. It has to cover the perforated floor without curling up the wall. Most baskets taper, so the floor is meaningfully smaller than the opening, and the gap is often bigger than people expect. Our 58 mm tapered basket is a clear example: it is in the 58 mm size class, but its perforated base measures 34 mm. A 58 mm disc has no business down there.
Sidenote: Do not improvise by trimming a top filter. A hand-cut edge leaves loose fibers and an uneven perimeter sitting right at the outlet.
Bottom paper can also change hydraulic resistance and shot speed. In one controlled series on a specific Decent Espresso setup, Coffee ad Astra measured lower stable puck resistance with a bottom paper filter. Read that as evidence the placement can move flow, not as a promise it will do the same in your machine with your basket and your coffee.
If a bottom filter makes the shot run faster, taste the cup before you decide what to change. Then make one small grind adjustment and repeat. Changing dose, grind and yield together tells you nothing.
A five-step fit check before brewing
- Identify the basket. Note the model, its recommended dose and whether the walls are straight or tapered. Our 18g vs 20g basket guide explains why a shared nominal diameter settles very little.
- Measure where the paper will sit. For the top, the usable inside diameter at the puck surface. For the bottom, the flat perforated area.
- Check the empty fit. The disc should lie flat, with no buckle, no folded edge and no pressing it into place.
- Check it again with a prepared puck. Use your normal dose and your machine maker’s clearance method. Stop if the portafilter does not engage the way it normally does.
- One paper, one shot. Discard it afterward. Wet paper loses its shape and carries coffee residue, and these discs are not specified as reusable.
A basket with published dimensions makes all of this easier. The 18 g crystalline titanium basket, for instance, lists a 70 mm outer rim, a 60 mm inner opening and a 24.5 mm height. Useful numbers, but note what is missing: no bottom-paper size. Published dimensions still do not authorize a 58 mm disc beneath the puck.
A three-shot test that keeps the comparison useful
- Shot one: baseline. Brew with no paper at your established dose, target yield and grind. Record beverage weight, time and how it tastes.
- Shot two: one placement. Add a correctly fitted top paper. Leave the coffee, dose, distribution, tamp and target yield alone.
- Shot three: repeat before adjusting. Run the same setup again. If the change holds up, adjust only the grind on the next shot. Test bottom paper as a separate series, never as a second variable inside this one.
A compact 0.1 g espresso scale with a timer keeps dose and beverage weight in view while you do it. Taste the samples at similar temperatures. A few seconds of difference in shot time, on its own, does not tell you which cup is better.
Troubleshooting paper-filter problems
| What you see | Check first | Next move |
|---|---|---|
| Top paper wrinkles | Paper diameter and an uneven puck surface | Use the correct size. Do not press an oversized disc into place |
| Handle locks unusually tight | Dose and available headspace | Remove the paper and recheck clearance before brewing |
| Bottom paper folds at the edge | Basket-floor diameter | Stop and get a purpose-sized bottom disc |
| Shot suddenly runs faster | Placement consistency and recorded yield | Repeat once, then adjust grind in a separate shot |
If the symptom is spraying or erratic flow rather than anything to do with the paper, the problem is upstream. Work through the puck prep checklist and our channeling troubleshooting guide first.
Who should skip espresso paper filters
Skip them if your shot is already stable and the extra step buys you nothing. Skip a top paper when headspace is tight to begin with. Skip bottom placement when the basket floor has no confirmed matching disc. Paper cannot correct an incompatible basket, an uneven tamp or poor distribution, and it is not a substitute for a clean group head.
For most buyers the safest first experiment is whatever placement the filter listing states. With Yozcoffee’s current 58 mm papers, that means above the tamped puck in a compatible basket. Treat bottom paper as a separate technique with its own diameter check and its own dial-in. If you are still assembling the rest of the setup, the full espresso gear collection lists baskets, screens and scales with their dimensions.
Gear for this test
Three pieces cover everything in the fit check and the three-shot comparison above. Confirm your basket dimensions before ordering.
Best for top placement
58mm Espresso Paper Filters, 200 Count
For top placement: one disc laid flat on the tamped puck, used once and discarded.
View the paper filters
Best reusable alternative
Stainless Puck Screen, 51/53/58mm, 2-Pack
The reusable alternative above the puck. Check headspace first, since it is thicker than paper.
View screen sizes
Best for the three-shot test
Mini Coffee Scale with Timer, 0.1 g
Tracks dose, yield and time so the three-shot comparison actually means something.
View the scaleFinal thoughts
A paper disc is a fit problem before it's a flavor experiment. On top, it has to lie flat on the puck and still let the portafilter lock in normally. Underneath, it has to match the perforated floor, which on a tapered basket can be far narrower than the 58 mm rim suggests.
Grab calipers or a ruler and measure two spots on your basket: the inside width at the puck surface and the flat perforated area at the bottom. Write both numbers down. Then brew a no-paper shot and one top-paper shot with everything else unchanged, and compare weight, time and taste.
Product specifications checked September 20, 2026.