What is the difference between a single and double basket?

In the world of espresso equipment, the filter basket is the foundation of your extraction. A single basket is traditionally designed to hold 7–10 grams of coffee, intended to produce a single shot. However, most single baskets feature a tapered, conical geometry. This shape makes it difficult to achieve an even coffee bed, often leading to channeling—where water finds the path of least resistance through the grounds—resulting in an unbalanced, thin, or sour cup.

Double baskets, by contrast, are the industry standard for modern espresso brewing. Designed to hold 14–20 grams of coffee, they typically feature straight or near-straight walls. This geometry allows for a more uniform puck depth and consistent water distribution, which is essential for achieving a balanced extraction. Because of this, most specialty coffee shops use double baskets exclusively, even when pulling a single serving.

When dialing in your espresso recipe, the basket size dictates your dose size. If you attempt to under-dose a basket, you risk a shallow puck that lacks the necessary resistance for proper pressure, while over-dosing can cause the coffee to touch the shower screen, leading to messy extractions. Always match your dose to the basket's rated capacity to ensure the puck provides the correct resistance.

In practice, most home baristas find that sticking to a double basket provides a more forgiving and rewarding experience. If you only want a single serving of espresso, it is often better to pull a double shot into a double basket and simply discard or save half, rather than struggling with the inconsistent performance of a single-shot basket. For those seeking the best flavor, the double basket is almost always the superior tool.