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What Are the Normal Extraction Time Parameters and Ratios for Espresso? Espresso Coffee Dose and Grind Size

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, When consumed straight, many people find espresso unbearable due to its high concentration of bitter, burnt flavors, often described as tasting like traditional Chinese medicine. However, when diluted with milk or water, it becomes much more acceptable to many palates. Unfortunately, reality is often harsh—you'll inevitably encounter coffees that remain difficult to swallow even after adding milk, or experience espresso art patterns that easily break apart.

The Challenge of Espresso

Many people find pure espresso difficult to drink due to its high concentration of bitter flavors, often describing it as similar to traditional Chinese medicine. However, when diluted with milk or water, it becomes more acceptable to many. Unfortunately, reality is often harsh—you may encounter coffee that remains unpalatable even with milk added, or notice that latte art patterns easily disintegrate. In many cases, these issues indicate problems with the espresso extraction itself.

Among FrontStreet Coffee's customers, many own espresso machines at home and enjoy making coffee occasionally. However, their frequency of operation is significantly lower compared to coffee shops. This makes extracting a delicious espresso much more challenging, requiring a simpler extraction theory and method.

The Challenge of Espresso Extraction

Even in coffee shops, issues like thin crema or overly bitter or sour espresso during extraction are not uncommon. Therefore, coffee shops typically calibrate their espresso until it meets quality standards.

What indicators can serve as references? The established parameters for espresso extraction are the relationship between time and the coffee-to-liquid ratio. Initially, the Italian Coffee Association guided the standard for espresso: extracting 30ml of espresso within 20-30 seconds. Today, coffee shops commonly use a 1:2 coffee-to-liquid ratio, with time serving as a reference factor and actual flavor assessment as the benchmark.

This shift is mainly due to the emergence of Single Origin Espresso (SOE) and variable pressure extraction machines, making extraction no longer one-size-fits-all but rather targeted extraction plans. For example, extracting traditional Italian blend coffee beans versus SOE Yirgacheffe coffee beans requires different parameters in terms of grind size, dose amount, time, and coffee-to-liquid ratio.

Making Espresso Seem Difficult Now

While current variable pressure extraction and immersion extraction may appear complex, as long as you understand the key factors of espresso and control these parameters well, it's actually difficult to extract a bad espresso.

For home coffee machines, your choice of equipment determines the difficulty of making coffee. Of course, having a double-head commercial coffee machine at home isn't realistic, but if you only have a small, supposedly powerful home coffee machine (often called "toy machines"), you're essentially starting at hell mode. FrontStreet Coffee believes that machines at the level of the Huijia 310 or above are suitable for beginners.

Coffee beans become the next challenge—how to select them becomes a significant learning curve. Online, prices range from 30 to 300 yuan, but FrontStreet Coffee wants to remind everyone: don't be tempted by cheap prices or buy low-priced "practice beans" to learn extraction techniques. While these beans might be fine for practicing repetitive actions, they make it nearly impossible to advance further.

From FrontStreet Coffee's experience, bad coffee beans often produce espresso with issues like bitterness, sharp acidity, or insufficient crema. If the problem is caused by the beans themselves, no amount of practice will help because you haven't experienced good coffee and don't know what it should taste like—this is a matter of cognition. Of course, once you truly understand what good coffee should taste like, buying some practice beans to reinforce your techniques is acceptable.

Bean Freshness

Regarding bean freshness, for optimal extraction results, espresso beans generally need about 7-10 days of resting (calculated from the roasting date). Beans that are too fresh will produce coarse crema and lack flavor development. Beans that are too old will have thin crema and flavors that tend toward bitterness and staleness.

Master These Basics for Easy Espresso

The difficulty in espresso extraction generally lies in controlling extraction time, preventing "channeling," and observing whether the espresso is extracting properly. FrontStreet Coffee has summarized several key points for beginners.

Time Control: For beginners, start by fixing the dose amount (based on portafilter capacity) and maintaining a 1:2 coffee-to-liquid ratio. Control extraction time within 25-33 seconds by adjusting grind size. This approach is very simple with only one variable. If extraction takes too long, make the grind coarser; if too short, make it finer.
Distribution and Tamping: However, beginners often add variables themselves through inconsistent distribution and tamping, which is also a cause of "channeling." FrontStreet Coffee's advice is to use a distribution tool for coffee distribution and apply maximum force when tamping—just ensure it's level. If your machine can maintain 9bar pressure during extraction, the difference in pressure from your hand is negligible, so don't worry about tamping too tightly.

Observing Extraction: During extraction, observe the coffee's extraction state, checking whether the flow rate is even and whether there's any spurting. If coffee spurts out 2-3 seconds after pressing the extraction button, you can determine that the grind is too coarse or "channeling" has occurred. If no liquid appears for more than 10 seconds after pressing the extraction button, you can stop the extraction and determine that the grind is too fine or there's too much coffee. If the flow rate is unstable—alternating between fast and slow—this is mostly caused by "channeling" or uneven tamping.

Troubleshooting: If you follow extraction requirements—extracting coffee in a 1:2 ratio within 25-33 seconds without "channeling" but still get thin crema—it's likely due to issues with the coffee beans (not fresh, roasted too light) or insufficient water temperature or pressure from the machine.

Advice for Pre-Ground Coffee Extraction

FrontStreet Coffee has also encountered many customers who need pre-ground espresso coffee. Regarding this, FrontStreet Coffee wants to emphasize that coffee grounds from coffee shops may not perfectly match your home machine. Similarly, even if you have the same equipment as a coffee shop, the shop may need to make daily minor adjustments to parameters, including grind settings, to ensure consistent coffee quality.

Therefore, pre-ground coffee can only provide us with an approximate coarseness level without precise control. For actual espresso extraction, with the grind size already fixed, we can only control extraction time by adjusting the amount of coffee grounds and tamping pressure to make the coffee taste better.

For example, if you're using 18g of coffee to extract 36g of liquid at a 1:2 ratio, but the flow is extremely slow and barely comes out of the portafilter, you can first try reducing the coffee by 1g and still aim for a 1:2 extraction. If the flow doesn't improve, you can reduce tamping pressure to allow hot water to better penetrate the coffee layer.