You have seen a paper disc placed above the coffee in one demonstration and beneath it in another. The positions look like interchangeable versions of the same trick, but they act at different points in the shot.
For espresso filter paper top vs bottom, start with the job you want done: separating grounds from incoming water, or putting paper in the outgoing beverage's path. Choose one compatible arrangement first. Adding both before you understand either makes the result harder to interpret, not automatically better.
Related product: Explore 18g Portafilter Basket. Check the product details for size, fit and availability.
Espresso filter paper top vs bottom: which job comes first?
Choose the position that matches your actual goal.
Top paper sits before water crosses the coffee bed; bottom paper sits after it, so the two positions should not be expected to provide identical beverage filtration.
Trace the route in a conventional basket: incoming water, coffee bed, perforated base, then cup. A disc above the grounds meets water before that water has extracted the coffee. A disc below the grounds is encountered by the brewed liquid before it exits. That placement distinction matters more than a general claim that "paper improves espresso."
Use the table as a starting decision, not a list of promised results. Physical compatibility is a separate requirement for either arrangement. If you cannot install the paper appropriately under the equipment and accessory instructions, do not proceed just to complete the comparison.
| Position | First question to test | Do not assume |
|---|---|---|
| Top | Does it change grounds contact above the puck? | Outgoing espresso is paper-filtered |
| Bottom | Does it change the outgoing shot? | Flow always slows down |
| Both | Does the second layer add a benefit? | Two layers outperform one |
What can top paper reasonably change?
It changes the interface above the coffee bed.
A top disc separates the grounds from incoming water and nearby brew surfaces, but any improvement in distribution or repeatability needs evidence from your particular arrangement and recipe.
Do not call that disc an outgoing beverage filter. The main espresso stream leaves below the coffee, not through the paper resting above it. A cleaner-looking upper surface therefore does not demonstrate that the drink contains fewer suspended particles or has a different oil concentration.
Top placement also adds something above the tamped bed. Establish compatibility without forcing the portafilter closed or borrowing a clearance rule from another machine. The broader accessory relationship is covered in Meraki's puck-screen guide; paper is not evidence that every arrangement involving a screen is suitable.
For this comparison, define a modest observation: whether the same preparation leaves a different amount of visible loose coffee at the upper brew interface after an ordinary shot. Inspect only when components are safe to handle. Keep that observation separate from flavor and extraction claims.
Why can bottom paper make a shot run faster?
An added filter need not increase total resistance.
Bottom paper changes the coffee-to-basket interface as well as adding material to the water path, so its net effect cannot be predicted by counting layers alone.
Jonathan Gagne's Coffee ad Astra experiment alternated shots with and without bottom paper and observed lower hydraulic resistance in the paper arrangement. Hydraulic resistance describes how strongly the system opposes flow. The experiment did not measure average extraction yield, so it should not be presented as a direct measurement of improved yield.
A related radial-extraction experiment examines extraction across different parts of the puck. It supports investigating the basket interface rather than treating the coffee bed as uniformly extracted. Neither source establishes a Meraki-specific improvement.
Your practical question is narrower: at a fixed dose and beverage endpoint, does your compatible bottom-paper arrangement repeatedly change delivery? Record that first. Do not prescribe a finer grind in advance merely because a published experiment found faster flow in its own setup.
Does bottom paper guarantee a better-tasting cup?
No; filtration and preference are different questions.
Bottom paper puts a filtering layer in the outgoing beverage path, but your preferred texture and flavor still depend on the coffee, recipe, and particular paper-and-basket arrangement.
Decide which sensory difference would actually help you. You might prefer a less gritty finish, or you might value a dense mouthfeel more than a perceived gain in clarity. Neither preference makes one paper position universally correct. Avoid deciding from crema height or an attractive stream photograph alone.
The World Coffee Research Sensory Lexicon offers defined coffee flavor attributes. It is a vocabulary resource, not a paper-placement trial. Its usefulness here is helping you describe a difference consistently rather than replacing every observation with "cleaner" or "better."
Taste at comparable temperatures and separate the observations: flavor, texture, and finish. If you cannot repeat the preference, keep the result provisional. This comparison does not measure oil content, dissolved-solids concentration, or a health effect, and those claims should not be inferred from the way one cup feels.
How do you compare positions without confusing the result?
Keep the first comparison deliberately limited.
Use compatible paper in one position at a time, preserve the same coffee and recipe settings, and repeat observations before adjusting grind or introducing another accessory to the test.
Begin with a repeatable no-paper reference, then compare top and bottom arrangements. Record the exact paper, its preparation, dose, beverage yield, and shot time. If the positions require different disc products, document that difference: you are comparing complete arrangements, not isolating location alone.
NIST's experimental-design guidance explains why design choices matter when interpreting an experiment. A home comparison does not become a laboratory study, but it benefits from deciding in advance what will vary and what counts as an observation.
Alternate the arrangements across a manageable set rather than brewing every top-paper shot first and every bottom-paper shot later. That reduces the risk of confusing position with a changing routine. Log unsuccessful outcomes too. A misplaced disc should prompt a fit or handling review, not disappear from your notes because it weakens your preferred result.
When should you re-dial each arrangement?
Re-dial after observing its initial effect.
First compare the arrangements at unchanged settings; then optimize a promising compatible arrangement separately, because a fixed-setting comparison and a best-recipe comparison answer different practical questions for you.
The first comparison asks what adding or moving paper changes in your current routine. The second asks which complete recipe you prefer after adjustment. Do not combine the answers. A bottom-paper shot at a new grind setting is not evidence that position alone caused every change you tasted.
Once you have an observation worth pursuing, adjust one recipe variable at a time and retain the endpoint you are trying to evaluate. If an arrangement requires a different dose for compatibility, record that change rather than claiming you held the recipe constant.
Meraki's built-in dose and yield scales can support recording those two quantities. They do not identify the cause of a flow difference or substitute for a taste comparison. Keep separate notes for the unchanged-setting trial and the adjusted recipe so you can explain why you chose the final workflow, rather than simply remembering the most enjoyable isolated shot.
Is less visible mess a reason to stop cleaning?
No; paper is not a machine-cleaning procedure.
Compare any change in visible grounds at the relevant interface, but retain the equipment's specified cleaning routine regardless of whether top or bottom paper makes disposal look tidier.
A top disc and a bottom disc leave you looking at different places. Inspecting the upper brew area is not the same observation as inspecting the basket's perforations. Record where the apparent benefit occurred instead of describing the entire machine as cleaner.
NSF's household hygiene guidance directs coffee-reservoir care to the manufacturer's recommendations. That is a separate care issue, not evidence that paper protects a reservoir or changes an espresso machine's maintenance schedule.
Use Meraki's machine-cleaning guide for the broader routine. Evaluate paper only for the extra task it changes: preparation, removal, or visible grounds handling. Include that effort in your decision. Saving a little cleanup time may be worthwhile, but not if it comes with unreliable positioning or a cup you enjoy less.
Should you use top and bottom paper together?
Only if the second layer earns its place.
After establishing compatible single-position arrangements, compare adding the second disc against the preferred one; retain both only when the added benefit is repeatable and worth the additional handling.
Define the missing benefit before adding another layer. If bottom paper gives you the drink you prefer, a top disc should answer a separate practical need. If top paper helps your upper-interface workflow, bottom paper should still justify its effect on the outgoing shot. "More filtration" is not an adequate description of both positions.
Compatibility must be reassessed for the complete arrangement, particularly when another accessory is already installed. Do not stack paper and metal components merely because each has been used individually elsewhere. An arrangement's total behavior cannot be guaranteed by adding together separate anecdotes.
Choose bottom paper first when your specific experiment concerns the outgoing beverage or basket interface. Choose top paper first when your question concerns the upper interface. Keep neither when the benefit is unclear. The goal is a repeatable cup and a manageable routine, not the greatest number of layers inside the portafilter.
Review the Meraki portafilter basket and confirm your paper's fit before brewing.
FAQ
Should I switch paper placement when I change coffee?
Not automatically. Keep your established arrangement while you dial in the new coffee, unless its recipe creates a compatibility issue that needs resolving first. Changing beans and paper placement together makes an unfamiliar result harder to explain. Once the new coffee gives repeatable shots, decide whether there is a specific reason to revisit placement. Your earlier preference belongs to its tested setup; it is useful background, not proof that the same arrangement must win with every roast.
Can I compare top and bottom paper using different disc products?
You can compare those complete arrangements, but you cannot attribute every difference to position alone. Different papers may also differ in dimensions, construction, and preparation requirements. Record each exact product and use it only where it fits appropriately. If the same paper is not suitable in both positions, do not force an artificial match. Describe your result as a comparison of two usable setups rather than claiming you isolated the effect of top versus bottom placement.
What if my results alternate between a better top shot and a better bottom shot?
Treat that as an inconclusive result, not an invitation to choose your favorite isolated shot. Check whether the preparation, endpoint, tasting temperature, and paper handling were consistent. Repeat a manageable comparison before making a permanent change, and keep the original observations rather than deleting the less convenient results. If the difference remains smaller than your ordinary variation, the simpler workflow is a reasonable choice. You do not need to demonstrate a winner to decide that extra complexity has not earned its place.
More on this topic: Portafilters, Baskets & Puck Preparation.
