Grinding for espresso has a significant impact on extraction, flavour structure, and consistency. Small changes in grind size can shift a shot from sharp to balanced, or from slow and heavy to fast and hollow. Understanding how grind affects your extraction helps create predictable and repeatable results.
If you are still learning how grind interacts with dose, yield, and shot time, see the How to Dial In Espresso at Home guide.
Grinding for espresso requires a fine, uniform grind to create enough resistance for proper extraction. The grind controls flow rate, impacts flavour clarity, and determines whether the shot extracts evenly. An inconsistent or inappropriate grind results in channeling, imbalance, or unstable crema.
Setting a Baseline
Start with a stable recipe so grind adjustments are meaningful. For most home machines:
18 g dose
36 g yield
25–30 seconds
This provides a consistent reference point. Adjust grind to correct flavour or flow rather than changing multiple variables at once.
Grind Too Coarse
A coarse grind reduces resistance, allowing water to pass through too quickly.
Expect:
sharp acidity
thin body
fast flow
weak or uneven crema
Correct by shifting the grinder slightly finer. One small step is usually enough.
Grind Too Fine
A fine grind increases resistance, slowing the shot.
Expect:
bitterness or dryness
heavy or restricted flow
long extraction times
dark, dense crema that breaks suddenly
Correct by shifting slightly coarser. Avoid making large jumps; small adjustments maintain control.
Consistency and Retention
Many grinders retain small amounts of ground coffee. Purging before each session removes stale grounds and improves flavour consistency. Keeping burrs clean, dosing accurately, and using a stable tamping technique further reduces variability.
Freshness and Age of Beans
As beans age, grind adjustments become necessary. Fresh beans (7–30 days from roast) often require a slightly coarser grind. Older beans may need a finer grind to maintain structure and balance. Adjust gradually as flavour and flow shift over time.
Espresso Ratios and Grind
Grind size is linked directly to brewing ratio. If you prefer a slightly higher or lower yield, adjust grind to maintain a balanced flow:
higher yield requires a slightly finer grind
lower yield often requires a slightly coarser grind
Keeping dose constant helps isolate the effect of grind changes.
Milk-Based Drinks
For milk drinks, a grind setting that produces a slightly faster and cleaner shot can improve balance once milk is added. Aim for clarity, structure, and a finish that cuts through milk without becoming overpowering.
Which Beans Respond Best
Medium and medium-dark blends provide consistent results across a wide range of grind settings.
Espresso Magic Reserve – medium-dark with cocoa and spice, strong structure and crema
Latte Luxe Reserve – medium roast with caramelised sweetness, ideal for milk
Café Classic Reserve – medium roast with balanced nuttiness and fruit
Single origins may require more frequent grind adjustments due to their natural variation, but reward with distinct and expressive flavour profiles.
The Takeaway
A clear understanding of grind size makes espresso more predictable and more enjoyable. Start with a stable recipe, make small adjustments, and monitor flavour and flow. With consistent technique and the right beans, grind adjustments become straightforward and reliable.
Explore blends, single origins, and Swiss Water Process decaf options in the Bean Buster Coffee collection.