You grind an espresso roast to a fine, even consistency that's slightly gritty, similar to fine sand but not as powdery as powdered sugar. This allows for proper extraction under pressure, resulting in a rich, flavorful espresso.
Understanding Espresso Grind
The ideal grind size is crucial for espresso because it affects the water's flow rate through the coffee grounds. Too coarse, and the water will rush through, resulting in under-extraction and a sour, weak espresso. Too fine, and the water will struggle to pass through, leading to over-extraction and a bitter, burnt taste.
Achieving the Perfect Grind
Here's a breakdown of how to grind an espresso roast for optimal results:
1. Use a Burr Grinder
Burr grinders are essential for espresso because they produce a consistent grind size. They crush the coffee beans between two revolving abrasive surfaces (burrs), ensuring uniformity. Blade grinders, on the other hand, chop the beans unevenly, which isn't suitable for espresso.
2. Adjusting the Grind Size
- Start with a Fine Setting: Begin with a fine grind setting on your burr grinder.
- Dialing In: "Dialing in" is the process of fine-tuning the grind size until you achieve the perfect extraction. This involves making small adjustments to the grinder setting and observing the resulting espresso.
- Observe the Extraction: Watch the espresso extraction closely. It should take approximately 25-30 seconds to pull a double shot (around 2 ounces).
- Too Fast (Under-Extraction): If the espresso pours too quickly, the grind is likely too coarse. Adjust the grinder to a finer setting.
- Too Slow (Over-Extraction): If the espresso drips slowly or not at all, the grind is likely too fine. Adjust the grinder to a coarser setting.
3. Grind Consistency Check
- Touch Test: Rub some of the ground coffee between your fingers. It should feel slightly gritty, like fine sand.
- Visual Inspection: The grounds should look uniform in size and color.
4. Freshness Matters
- Grind Immediately Before Brewing: Coffee beans lose their flavor quickly once ground. Grind only the amount of coffee you need for each espresso.
- Store Beans Properly: Keep your espresso roast beans in an airtight container in a cool, dark place.
Example Scenario
Let's say you're using a new bag of espresso roast and your grinder is set to a medium-fine setting.
- Pull a Shot: Pull an espresso shot and observe the extraction.
- Extraction Time is 20 Seconds: The espresso pours too quickly, indicating under-extraction.
- Adjust the Grind: Adjust the grinder to a slightly finer setting.
- Repeat: Pull another shot and observe the extraction time.
- Extraction Time is 28 Seconds: This is much better, but still slightly off.
- Fine-Tune: Make a small adjustment to a slightly coarser setting.
- Optimal Extraction: After further fine-tuning, you reach a 26-second extraction, which is ideal.
By consistently evaluating the extraction and making small adjustments to the grind, you can consistently achieve the perfect espresso.
