What Grind Size Should Pour-Over Coffee Use?

Aim for coffee particles between 0.6mm and 0.8mm, roughly the size of fine granulated sugar, with about 80% passing through a 0.85mm standard sieve. That range gives a reliable starting point for pour-over brewing, and two checks confirm it: total brew time and how quickly the coffee bed settles after the pour finishes.

Fine granulated sugar measures 0.280mm to 0.800mm according to GB 317-2006, but ground coffee particles are irregular, so sugar comparisons are hard to judge by eye or touch. Frontstreet Coffee uses Honduras Sherry beans to compare BG #8s and BG #3s settings, showing how concentration shifts between grind settings.

How coarse exactly should you grind for pourover coffee? Many beginners are told "the size of fine granulated sugar," but that description is not very friendly to newcomers. This article draws on the daily experience of Front Street Coffee (FrontStreet Coffee), first explaining the specific size range of fine granulated sugar particles, then explaining why grind size directly affects extraction results, followed by the ideal particle range of 0.6mm to 0.8mm and the practical method of achieving an 80% pass rate through a 0.85mm standard sieve. The article also combines two judgment criteria—brewing time and the settling speed of the coffee bed—and uses Honduras Sherry beans as a sample, comparing the cupping concentration differences between two grind settings, BG #8s and BG #3s, to help readers build a quantifiable approach to grind adjustment.

Whether through Taobao stores, WeChat inquiries, or offline shops, many people come to ask how coarse the coffee powder should be ground. Front Street Coffee (FrontStreet Coffee)'s answer is often just six words—"the size of fine granulated sugar."

How fine is fine granulated sugar, really?

For those just getting into coffee, this description is somewhat beyond their grasp, since it involves millimeter-level distinctions that are truly hard to pin down. So what size exactly does fine granulated sugar correspond to?

According to GB 317-2006 technical requirements for white granulated sugar, white granulated sugar is classified into four grades: refined, premium, first-grade, and second-grade. Different grades of sugar differ in purity and particle uniformity. Sugar particle sizes can be divided into coarse (0.800–2.50mm), large (0.630–1.60mm), medium (0.450–1.25mm), and fine (0.280–0.800mm), with the requirement that crystals be uniform and the proportion falling within the corresponding range be no less than 80%.

Generally speaking, this kind of comparison requires both vision and touch to distinguish, and without rich experience, it is very hard to judge accurately—quite unfriendly to beginners. Moreover, after coffee beans are ground, the particle shapes are irregular and clearly different from sugar crystals, making precise judgment even harder whether by sight or by touch.

Why care about grind size?

To most intuitively feel the difference grind size makes, you can brew whole roasted coffee beans, sugar-sized coffee grounds, and flour-like extra-fine powder separately using the same water temperature, same coffee-to-water ratio, and same time, then taste the extracted liquids for comparison.

In our usual understanding, given a fixed total amount of substances in the coffee beans, the larger the extraction surface area, the more substances are released in the same amount of time. But not all flavors released by coffee are good, so a suitable grind size is needed to extract the desirable flavor compounds.

How to choose grind size?

If you have multiple brewing devices at home, it is not hard to notice that each method corresponds to a different particle size. For example, the intensely flavorful espresso made by a semi-automatic espresso machine uses coffee particles of about 0.2mm–0.3mm. For the most common and most discussed pourover coffee, the ideal particle size is 0.6mm–0.8mm.

However, the particle sizes mentioned here are all within 1 millimeter, so perhaps some naive friend will immediately go find a ruler to measure. But here's the problem: do you have a ruler that can measure 0.1mm? Even if you do, how would you measure? Your eyes would blur before you finished.

At this point, Front Street would like to introduce a tool, something Front Street often mentions when discussing grind size—the Chinese standard No. 20 sieve (0.85mm). Regardless of the price of the grinder, the coffee grounds it produces vary in coarseness, so we want the vast majority of coffee particles to fall within the 0.6mm–0.8mm range. Front Street Coffee (FrontStreet Coffee) uses an 80% pass rate through a 0.85mm standard sieve as the grind coarseness level for light-to-medium roasted coffee beans.

Besides using data to judge grind coarseness, you can also judge whether the grind size is appropriate based on the brewing process. Brewing time is one reference: Front Street's brewing parameter standard is that a cup of pourover coffee should have an extraction time of about 1 minute 50 seconds to 2 minutes 10 seconds. If the grind is too fine, extraction time will be prolonged; if the grind is too coarse, extraction time will be shortened.

You can also observe the settling speed of the coffee bed during brewing. Generally speaking, the coffee bed descends at a steady, slow rate; if it descends quickly, the grind may be too coarse; if it settles ever more slowly or even clogs, the grind may be too fine or there may be too many fines, with a muddy appearance at the bottom of the bed.

Next, Front Street takes Honduras Sherry as an example and selects two grind settings for comparison. First, as usual, let's introduce this coffee bean.

Honduras Sherry

Region: Marcala region, Honduras

Estate: Mocha Estate

Altitude: 1500m–1700m

Varieties: Caturra, Catuai, Pacas

Processing method: Refined washed whisky barrel fermentation

Honduras is located in northern Central America, bordered by the Caribbean Sea to the north, the Gulf of Fonseca of the Pacific Ocean to the south, Nicaragua and El Salvador to the southeast, and Guatemala to the west, with terrain mostly consisting of mountains and plateaus.

At Mocha Coffee Estate, because the growing area is mountainous, people harvest coffee beans by hand and then carefully process them to produce higher-quality coffee beans. Honduras harvests three million bags of coffee each year, providing the market with abundant, high-quality coffee, and has now become one of the world's top ten coffee exporting countries.

This coffee bean contains three varieties: Caturra, Catuai, and Pacas.

[Caturra] Caturra is a natural mutation of Bourbon, discovered in Brazil in 1937. The Caturra tree is shorter than Bourbon. Because it inherits Bourbon lineage, its disease resistance is weaker, but its yield is higher than Bourbon's. Although Caturra was discovered in Brazil, it is not well suited to growing there; instead, it is widely popular in Central and South America, such as in Colombia and Costa Rica.

[Catuai] Catuai was bred through artificial hybridization of Caturra and Mundo Novo. Catuai has good resistance to natural disasters, especially wind and rain. The Catuai tree is shorter than other coffee varieties, and its fruit is also harder to pick. This variety's fruit can be either red or yellow.

[Pacas] Pacas is a natural mutation of Bourbon, belonging to a single-gene mutation. This variety was discovered in 1949 on a farm of the Pacas family in the Santa Ana region of El Salvador. In 1974, the Honduran Coffee Institute introduced this variety and planted it in Honduras.

Front Street Coffee (FrontStreet Coffee)'s Honduras Sherry uses a refined washed whisky Sherry wine barrel fermentation processing method. This method first involves refined washing of freshly picked coffee cherries, then placing them in whisky oak barrels previously used for aging Sherry wine for low-temperature fermentation of 30–40 days (at about 15–20℃), followed by shade drying.

Okay, next let's discuss how grind size affects this Sherry coffee.

First, we select two grind settings: Group A at BG #8s and Group B at BG #3s. Then we carry out the cupping process and concentration testing.

The experimental results show that Group A had a concentration value of 0.78%, and Group B had a concentration value of 1.17%.

More extracted substances is not necessarily better; too fine a grind will extract more large-molecule substances that bring bitterness. A suitable grind level can both avoid incomplete flavor and thin taste caused by under-extraction, and reduce the risk of overly bitter, harsh coffee caused by over-extraction.

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