Espresso is the foundation of Italian coffee. The wide variety of milk coffees we see on café menus are mostly based on espresso. In addition, although many people like espresso with milk, there are still a group of enthusiasts who love espresso.

No matter from which perspective, making a good single or double espresso is of utmost importance. Espresso is also a great test of a barista's skill. Among the factors that affect espresso flavor, the espresso grind size is a particularly key factor. How can you adjust to the correct espresso grind size?

One thing we need to be clear about is that dialing in the espresso grind size is not a one-time fix. Changes in the condition of the coffee beans and changes in air humidity will often affect espresso extraction. Therefore, the grinder needs to be fine-tuned to adapt to these changes. Generally, every morning we check whether the grind size is suitable for extraction with these parameters. Sometimes when the weather changes frequently, the grind size adjusted in the morning deviates by the afternoon, and it needs to be readjusted.

Here Front Street would like to specially explain that sometimes extraction is unstable and the grind needs to be adjusted frequently. Besides unavoidable reasons such as weather, there is another important reason: the freshness of the coffee beans. Coffee beans that are too fresh contain abundant gas, which makes extraction unstable and also limits the flavor. Espresso coffee beans generally have a longer resting period. If you want the beans to be more stable, it is recommended to rest them for no less than 2 weeks.

Adjusting to the appropriate espresso grind size can only be done through repeated extraction adjustments. Before dialing in the grind, we need to be clear about a few goals. First, why does the grind need to be adjusted? Because the extracted espresso does not meet our preset requirements, including extraction parameter requirements and flavor. Second, when dialing in the grind, other parameters should be kept as consistent as possible, such as skilled and precise distribution and tamping techniques, and consistency in dose and yield; otherwise, your grind adjustment will be full of uncertainties.

Here is a simple and quick way to determine the grind size. First, apply the extraction parameters of a 1:2 coffee-to-water ratio and a time of 20-30 seconds. The dose is calculated according to the recommended capacity of the basket; for example, a 20g basket holds 20g of coffee. Then first choose a grind setting (it looks like flour in coarseness), then extract and check the time. If the time exceeds 30 seconds, the next extraction needs to be adjusted coarser. If the time is less than 20 seconds, the next extraction needs to be adjusted finer.

After the extraction time is controlled at20-30seconds, we then fine-tune by tasting the espresso. If the coffee has insufficient aroma and is overall too sour, it needs to be adjusted finer; if the coffee is burnt and bitter and unpleasant, it needs to be adjusted coarser.

The above content is compiled by CoffeeHunters, a coffee news website.