Modern filter baskets have revolutionized espresso extraction. They’ve gone from being mundane accessories to crucial components on your coffee bar. The latest designs of these baskets make a significant difference in extraction efficiency and flavor.
The key feature of these modern high extraction filter baskets is the hole pattern at the bottom. Manufacturers have redesigned these holes to ensure even extraction to the edges and faster flow through the coffee bed, allowing baristas to use finer grind sizes and achieve higher extraction yields.
Interestingly, the baskets we’ve tested show radically different approaches to maximizing flow, despite their common goal. To understand this, we reached out to Professor Abbott, who developed a new app for us called the Basket Hole Analyser. This app lets users analyze the size, placement, and total open area of the holes at the bottom of their baskets. You can even verify manufacturers’ claims about their baskets.
Our tests revealed that the new designs indeed allow higher flow rates and extractions, but they achieve this in vastly different ways. For example, the Sworks Billet baskets use many tiny holes to enable fast flow, while the Pesado HE% baskets rely on larger, closely-packed holes to maximize the open area.
Using the Basket Hole Analyser app, we discovered that the Sworks Billet basket has a total open area of 4%, while the Pesado’s large holes make up 14% of its total area. Despite these differences, both baskets provide similar results. One might think that different hole sizes and open areas would result in varying resistance to the flow of espresso, but these differences are minimal compared to the resistance from the coffee puck itself.
Another fascinating finding is that modern baskets allow flow closer to the edge of the puck and seem to prevent clogging by coffee particles. The app also provides insights into the uniformity of hole sizes and spacing, which likely contributes to even extraction across the puck. The Sworks basket uses a Fibonacci spiral pattern for its holes, while the Pesado basket uses concentric rings. This difference in design shows up clearly in the app’s visualizations.
To use the app for your own baskets, a high-contrast photo of the inside of the basket is crucial. This requires a high-resolution camera, preferably with a telephoto macro lens, and proper alignment. The app needs a well-lit, high-contrast image to analyze the hole pattern accurately.
For blocked holes, Professor Abbott advises not to worry much, as a few blocked holes won’t significantly affect the data. However, for those wanting perfection, options like compressed air or an acupuncture needle can help clear blockages.
Once the photo is ready, upload it to the app, enter the basket diameter, and follow the instructions to analyze the basket. The app reveals detailed data that underscores the precision of modern basket manufacturing. These advancements in basket design can lead to better-tasting shots and make the investment worthwhile for busy cafes.
If you’re skeptical, try using the app to analyze your current baskets. Investigate how evenly sized and spaced the holes are and how much of the puck isn’t properly extracted. This might just convince you that it’s time to upgrade your expectations for filter baskets.