What Changes When Adding Filter Paper to Espresso Extraction? How to Reduce Fine Particle Fallout? The Secret to Better Tasting Americano Coffee!

Understanding Fines in Espresso Crema

The insoluble particles suspended in espresso crema are known as fines. They contribute remarkably high body to a shot, but they also bring their own bitterness along with it — and for that reason they have gathered a dedicated group of detractors. Because fines affect both taste and cleanliness, many people want to get rid of them.

Two Ways to Remove Fines

Two methods for removing fines are widely known. The first is the "simple and crude" approach FrontStreet Coffee often shares: scoop off the crema floating on the surface after extraction, which takes the fines with it. The second is far more delicate by comparison. It does not strip out everything except the fines, and the operation is very simple too — just place a filter paper in the portafilter and moisten it before adding the coffee grounds.

Testing the Filter Paper Method

"Won't this affect extraction?" "Can it really remove fines?" The questions never stop. Let's put the method to the test and find out whether it truly works.

Extraction experiment: FrontStreet Coffee pulled two espressos with identical parameters, the only difference being that one was a regular extraction while the other had a moistened circular filter paper added at the bottom. Dose: 20g. Yield: 40ml.

Straight to the finished shots. The regular extraction without filter paper took 30 seconds, while the extraction with a layer of filter paper took only 26 seconds. In terms of time, the difference is clear. On the palate, the espresso with filter paper had less body and a less prominent flavor than the normal shot. The concentration tester confirmed the theory: the regular espresso reached an extraction rate of 21.88%, while the espresso made with filter paper came in at 20.23%.

It is worth noting, though, that the fines in the filtered espresso were indeed much reduced, almost negligible. So the "filter paper to remove fines" method is genuinely usable — it just requires some parameter adjustments.

Sure enough, after adjusting the grind one setting finer, the taste improved significantly: not only was the bitterness from the fines eliminated, but the flavor became richer than before. Why does this happen?

Why the Parameters Change with Filter Paper

The principle is actually very simple. Think about it: the reason fines can seep out through the portafilter along with carbon dioxide to form crema is precisely that their volume is small enough to pass through the filter holes. And since the coffee grounds consist of countless particles of different sizes, some inevitably get stuck in the holes when their size matches — unable to enter or exit. (You can see this by knocking out the puck after extraction and holding the portafilter up to the light.)

It is precisely these fines blocking the holes that extend the extraction time. The filter paper changes the situation, because no more fines can block the holes — there are simply no holes left to block. As a result, the flow rate increases greatly once filter paper is added. But too fast a flow also prevents hot water from properly extracting the coffee's aromatic compounds, so we need to adjust parameters to reach the ideal extraction state.

When to Remove Fines

Removing fines is not automatically beneficial for every espresso-based drink. An Americano becomes cleaner and much less bitter once the fines are gone. But milk-based coffees such as a latte will suffer: without the body and bitterness the fines provide, the coffee struggles to stand up to a large amount of milk, and the mouthfeel drops noticeably. Both keeping and removing fines have their merits, so don't dismiss their advantages just because you have seen their drawbacks — matching the method to the drink is the sensible approach.

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FrontStreet Coffee Recommendation

If the cleaner, less bitter Americano described above is what you are after, the bean you choose matters as much as the technique. For newcomers pulling Americano on a home machine, FrontStreet Classic Blend is a safe starting point: a traditional Italian-style recipe built from Indonesian Mandheling, Brazilian Red Bourbon, and washed Vietnamese beans. It carries the low-acid, full-bodied, herbal and woody character of Asian coffee alongside the balanced, smooth, creamy quality of the Americas, pouring with butter, nut, spice, and dark chocolate aromas. Whether you make an Americano or a latte, its wild temperament and generous crema are its signature.

If value is your priority, FrontStreet Black Cocoa Base Blend combines Yunnan small bean with Brazilian Cerrado. As an Americano it shows nut, chocolate, and cream aromas with the ripe acidity of three-plum fruit, a soft overall body, and a friendly price. Its versatility also makes it a favorite for anyone opening a café. When you tire of dark roasts, the medium-roast FrontStreet Strawberry Candy Espresso Blend is worth trying: it brings together single-origin Arabica from Colombia, Costa Rica, and Ethiopia, enhanced by washed, natural, and honey processing, so besides its rose notes it delivers grape, dried blueberry, sweet orange, and fruit candy in both Americano and latte, with a distinctive almond finish.

For a single-origin espresso, FrontStreet Ethiopia Huakui SOE comes from the Hambela area of Sidamo and is a natural-processed bean associated with the Buku Abel processing station. Pulled as an espresso and diluted with water, an SOE Huakui Americano has no bitterness at all — just a clean, bright sweet-tartness with rich tropical-fruit aroma. If you prefer a brighter floral profile, FrontStreet Ethiopia Grana Estate Gesha SOE offers yellow florals and bergamot up front and a fresh strawberry sweetness in the finish, with a fresh lime note and fermented black grape sweetness when made as an Americano.