Barista Tips—How to Adjust Grind Size When Making Espresso, Espresso Brewing Guide

Espresso Coffee Grind Issues

For drip-style coffees like pour-over and cold brew, the coffee particles themselves are ground relatively coarsely, and we can even use a sieve to distinguish them. However, espresso machines require the finest possible grind, which appears dust-like to the naked eye.

Moreover, there are two issues with espresso grind size. First, different espresso machines have slightly different requirements for grind fineness. Second, grinding coffee beans into such fine powder can cause wear on the burrs, and significant wear can affect the grinder's precision. This is particularly relevant to the first reason: when some customers have espresso machines but no grinders, FrontStreet Coffee can only pre-grind coffee according to the grind settings used for their own production, which can result in grind sizes that don't perfectly match different machine specifications. (The relationship between grind size and machines will be discussed below)

Why Frequent Grind Adjustments Are Necessary

The term "frequent" here is in comparison to pour-over coffee. In pour-over brewing, the grind setting for each coffee bean variety remains basically constant, while espresso grind size needs adjustment at least 1-2 times daily.

The reason lies in the influence of daily atmospheric pressure and humidity, combined with grinder precision issues. Although the ground coffee may appear identical to the naked eye, when locked into the coffee machine and the extraction button is pressed, whether it's too coarse or too fine becomes immediately apparent. Therefore, we need to adjust espresso grinders daily to accommodate the "picky" coffee machine (after all, the espresso machine has half the say in whether the espresso tastes good).

How to Adjust Grind Size for Espresso

In daily operations, the main parameter adjusted for espresso is grind size, and these adjustments often involve barely noticeable increments of just 0.1 divisions. Before adjusting the grind, we need to clarify several goals. First, why adjustment is needed—because the extracted espresso doesn't meet our preset requirements, including extraction parameters and flavor. Second, when adjusting the grind, other parameters should remain as consistent as possible, such as skilled puck distribution and tamping techniques, and consistent dose and yield volumes. Otherwise, your grind adjustments will be filled with uncertainties.

Espresso grinders typically have a horizontal flat burr structure with an adjustment dial marked with graduations—higher numbers indicate coarser grinding. Taking the Fiorenzato grinder used by FrontStreet Coffee as an example, espresso grind size hovers between 1.5-2.5. In daily adjustments, we follow an extraction formula principle based on dose, extracted coffee liquid, and extraction time. The dose and extracted liquid form a dose-to-yield ratio, typically 1:2, while extraction time falls between 20-30 seconds.

For example, when FrontStreet Coffee used 20 grams of coffee to extract 40 grams of espresso liquid in 18 seconds, this was clearly too fast, meaning the coffee was ground too coarsely and needed to be ground finer. Since 18 seconds isn't far from the 20-30 second range, we could adjust finer by 0.1-0.2 divisions. After FrontStreet Coffee adjusted 0.2 divisions finer, the extraction time became 23 seconds, which fits the extraction formula, but it doesn't necessarily guarantee good taste, so tasting is still required to identify shortcomings and make further fine adjustments.

Another example: when FrontStreet Coffee used 20 grams of coffee to extract 40 grams of espresso liquid in 48 seconds, and the first drop of coffee appeared after 15 seconds, after confirming that the dose and tamping were not problematic, we determined the coffee was ground too finely. The resistance from the overly fine coffee grounds was too high, preventing water from penetrating the coffee puck. Therefore, we needed to adjust coarser. Since the 48-second extraction was far from the 20-30 second range, we could first adjust 0.5 divisions coarser and observe the extraction time, gradually adjusting back. Typically, 2-3 extractions are needed to determine the optimal setting.

Extraction Suggestions for Home Espresso Machines

Many enthusiasts have espresso machines and grinders at home but consume relatively small amounts, perhaps only 1-2 cups per day. Having to adjust 2-3 times daily for just 1-2 cups would clearly be somewhat wasteful and laborious. For this situation, FrontStreet Coffee offers the following suggestions:

1. Use the maximum dose recommended for your portafilter basket. For example, the reasonable capacity of the portafilter basket used by FrontStreet Coffee is 18-20g, and selecting a 20g dose would be more stable.

2. Due to low daily output, grinder wear won't be a significant issue. You can adjust the grind setting properly when first using it and record that setting. For daily extractions of one or two cups, simply follow that grind setting, maintain a 1:2 dose-to-yield ratio, and keep extraction time within 20-30 seconds.

Some might ask: there's a 10-second difference between 20-30 seconds—if one extraction takes 20 seconds and another takes 30 seconds, is the difference significant? First, it's certain that there will be a difference, but both generally fall within the acceptable espresso extraction range. If you're not drinking espresso straight but adding milk to make lattes or water to make Americanos, the difference will be significantly minimized. Unless you're conducting academic research, there likely won't be major negative sensory differences in flavor tasting.

A good espresso features well-balanced acidity, sweetness, and bitterness, with prominent flavors and a long-lasting aftertaste.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473