Introduction:To brew a pour over with balanced flavors, grind size is one of the key variables. However, comparisons like "granulated sugar fineness" remain vague for beginners. This article delves into the ideal grind range for pour over coffee—from particle sizes between 0.6mm and 0.8mm, to the scientific basis of an 80% passing rate through an 0.85mm sieve, to how brew time and bed settling speed can indicate whether your grind is appropriate. Backed by actual cupping data, it helps coffee enthusiasts master quantifiable adjustment techniques.

Much of the charm of pour over coffee lies in the control of details, and grind size is a crucial factor that affects flavor expression. Many beginners are often advised to grind coffee beans to the "fineness of granulated sugar" when they first try pour over, but such a description is actually imprecise and hard to apply practically. What exactly is the fineness of granulated sugar? Why is grind size so important? And how can you adjust it accurately to the right range? This article will guide you step-by-step through the answers.

First, let’s clarify just how fine “granulated sugar” really is. According to China's national standard GB 317-2006 on white sugar classification, sugar can be categorized by particle size into coarse (0.800～2.50mm), large (0.630～1.60mm), medium (0.450～1.25mm), and fine (0.280～0.800mm). The commonly referenced “granulated sugar” usually falls within the 0.280～0.800mm range, though this varies by grade. However, coffee grounds have irregular shapes and differ significantly from sugar crystals—judging by touch or sight alone, even seasoned baristas can rarely tell at a glance if it’s just right.

So why does grind size have such a big impact on coffee extraction? Simply put, the finer the grind, the greater the total surface area of the coffee grounds, allowing more water contact and the release of more flavor compounds. But not all of these compounds are desirable—over-extraction can bring out excessive bitter and astringent large molecules, while grinding too coarse may lead to under-extraction, making the coffee taste thin and dull. Therefore, finding a grind size that fully releases desirable flavors without introducing undesirable impurities is the first step to a successful pour over.

For pour over coffee, the ideal grind particle range is generally recommended to be between 0.6mm and 0.8mm. This range ensures a moderate flow rate of water, achieving a good balance of acidity, sweetness, and moderate body. But here’s the question: how can we confirm whether our home grinder is producing this range? Do we really need to measure each coffee ground with a ruler?

In fact, it’s not that complicated. A common and practical reference tool in the industry is China’s standard No. 20 sieve, which has a mesh diameter of 0.85 millimeters. This sieve can be used to screen coffee grounds and check what proportion of the powder can pass through. It is generally recommended that for medium to light roasted coffee beans, about 80% of the coffee grounds should pass through an 0.85mm sieve. Such a sieve passing rate allows us to scientifically gauge grind fineness, rather than relying solely on vague analogies.

In addition to using a sieve test, actual brewing performance is also an important basis for judging whether the grind size is appropriate. Among these, “brew time” is a straightforward indicator. The ideal extraction time for a typical pour over falls between 1 minute 50 seconds and 2 minutes 10 seconds. If the brew time is too long, exceeding 2 minutes 30 seconds, it likely indicates the grind is too fine, causing water resistance and over-extraction; conversely, if the brew finishes in just 1 minute, the coffee may taste overly weak, possibly due to the grind being too coarse and the water flowing too fast.

Another detail worth observing is the “bed settling speed.” During the pour over process, after hot water is poured onto the coffee bed, the coffee grounds should settle slowly and steadily. If the coffee bed settles too quickly, it may suggest the grind is too coarse, allowing water to pass through too easily; if the coffee bed settles slowly or even becomes clogged, forming a muddy state at the bottom, it may indicate the grind is too fine, with too much fine powder causing poor drainage, which also affects overall extraction performance and flavor presentation.

To more clearly illustrate the real impact of grind size on coffee flavor, we take a Honduran coffee bean processed with the sherry method as an example, conducting cuppings with two different grind settings: Group A used a BG #8s grind, and Group B used a BG #3s grind. The experimental results showed that Group A had a concentration of 0.78%, while Group B reached as high as 1.17%. Concentration levels directly reflect the amount of extracted material; excessively high concentration often means too many large molecular substances have been released, potentially leading to noticeable bitterness and astringency, affecting overall flavor balance.

Combining the above practical experience and data, we can conclude: controlling the pour over grind size between 0.6mm and 0.8mm, along with an 80% passing rate through an 0.85mm sieve, is the most suitable reference standard for most medium to light roasted beans. At the same time, paying attention during brewing to whether the time falls between 1 minute 50 seconds and 2 minutes 10 seconds, and observing whether the coffee bed settles at a uniform speed, can effectively help you adjust to the optimal grind fineness, thereby enhancing the flavor performance of every cup of pour over coffee.

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