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Understanding Espresso Episode 3 Brew Time by James Hoffmann

I. Defining and Understanding Brew Time​

  • Definition: Brew time is defined as the entire duration from pressing the start button until pressing the stop button on the espresso machine.
  • What it Measures: Brew time tells you how much resistance the coffee puck offered to the consistent water pressure. It is directly impacted by two main variables:
    1. Dose (Amount of Coffee): More coffee means more resistance.
    2. Grind Size: Finer grounds fit together better, creating smaller gaps and higher resistance.
  • Usefulness: Recording brew time is useful for understanding the impact of a change you made (e.g., if you changed the grind size, the resulting brew time indicates the level of resistance change).

II. The 25–30 Second Rule​

The recommendation that espresso brew time should be in the region of 25 to 30 seconds is a good starting point for beginners.

  • Reasoning: This time frame is not a target in itself, but a consequence. Achieving your ideal coffee-in to coffee-out ratio in 25–30 seconds requires a grind size that exposes the right amount of surface area for a good-tasting espresso.
  • Beginners: The 25–30 second window is most useful for beginner to intermediate espresso makers to establish a consistent, solid foundation.
  • Advanced Users: Once you understand the mechanics, you can break the rule intentionally to achieve specific results (e.g., a 16-second shot or a shot with a long pre-infusion).

III. The Impact of Pressure and Flow​

Brew time can be manipulated on advanced machines with pressure or flow profiling, but this does not necessarily increase extraction:

  • Pressure Reduction: Testing showed that reducing pressure during the latter half of the shot resulted in a slower shot (longer contact time), but did not increase the overall extraction.
  • Long Pre-Infusion: A very long pre-infusion time adds a small amount of extraction, but this is often counterbalanced by a faster flow afterward. It doesn't typically increase extraction unless you grind significantly finer.

IV. Conclusion​

The taste is the ultimate target, and brew time is merely a piece of data. For standard machines, hitting the 25–30 second window is a good indicator that your dose and grind size are in the right ballpark for a good-tasting shot.