Why is my espresso shot pulling too slow?

When your espresso shot pulls too slowly—or stalls entirely—it is a sign that the water is struggling to penetrate the coffee puck. This is almost always a result of the grind size being too fine. When the particles are too small, they pack together so tightly that they create a nearly impermeable barrier. To fix this, adjust your grinder to a coarser setting, which will allow the water to flow more freely.

Before you change your grind, however, check your dose. If you have overfilled the basket, the coffee may be pressing against the shower screen, which can restrict water flow and cause the shot to stall. Ensure you are using the correct dose for your basket size. Additionally, while tamping pressure is often overrated, an extremely uneven or overly compressed puck can sometimes contribute to flow issues, though the grind size is almost always the primary culprit.

If you have adjusted your grind and dose but the shot is still slow, consider the age of your beans. Very fresh coffee contains high levels of CO2, which can create significant resistance during extraction. If your beans were roasted within the last few days, they may need more time to degas. Conversely, if your machine's pressure is set too high, it can compress the puck during the brew, further slowing the flow.

In practice, the goal is to achieve a balanced extraction within a reasonable time frame, typically 25–30 seconds for a standard double shot. If your shot is taking 45 seconds or more, it is likely over-extracted and will taste bitter or burnt. By systematically adjusting your grind size and ensuring your dose is consistent, you can find the flow rate that produces the best flavor. Always make one change at a time so you can clearly see the impact on your results.