The Perfect Grind: How Fine Should Your Pour-Over Coffee Be? Your Complete Reference Guide to Coffee Grind Sizes

A delicious cup of coffee is hard to come by, as the journey from seed to cup is a very long wait. Even at the final extraction step, you must ensure that the coffee you're using meets brewing standards. Extraction is easy, but have you ever considered that coffee grounds are what extract the flavor compounds? The water, beans, equipment, and other elements used all significantly impact the flavor presentation of a cup of coffee.

Today, we're discussing coffee grind size. This is not simple, because even grinders from the same brand are not identical. These subtle differences in grind can be enough to affect the coffee grounds. Coffee grounds cannot be prepared simply by grinding them into powder like soy milk. That's why grinders have so many grind settings - you need to make fine adjustments to find the appropriate grind size; otherwise, even the best coffee beans are meaningless.

The Importance of Grinding

Grinding relates to coffee extraction issues. The finer the grind, the higher the extraction rate; the coarser the grind, the lower the extraction rate. This involves three factors: contact time, extraction rate, and flow rate. These relationships are complementary - one inevitably affects another.

• The extraction rate of coffee grounds increases with the increase in surface area as they are ground into powder.
• An increase in surface area means a finer grind, while a decrease in surface area means a coarser grind.
• The finer the coffee grind, the higher the extraction rate, resulting in shorter contact time.
• The finer the coffee grind, the slower the water flow and the longer the contact time; the coarser the coffee grind, the faster the water flow and the shorter the contact time.

This is easy to understand: espresso machines use extremely fine grounds, so espresso extraction takes only about 30 seconds; pour-over coffee uses medium-fine grounds, so contact time is around 2 minutes. When you want to use a specific coffee brewing method, you need to set the grind size accordingly - finer or coarser. If you use extremely fine grounds to make pour-over coffee, the water flow will inevitably slow down, resulting in longer contact time and higher extraction rate. Conversely, if you use medium-fine grounds to make espresso, the contact area is small, water flow is fast, extraction time is short, and extraction rate is low.

Even if you're grinding at the right size for pour-over coffee, how do you verify that your grind size is correct? Even a slight deviation can result in different flavors. Therefore, coffee grind size needs to be adjustable, allowing you to achieve the best possible results in coffee preparation.

It's worth noting that many people mistakenly believe that grounds from the same grind setting are the same size. In reality, different grinders have certain assembly errors and can be calibrated regularly. Similarly, you can use standard sieves to measure the fineness of the grounds to select the appropriate grind size.

FrontStreet Coffee's grind size standard sieve pass rates are as follows:

Cold drip > Pour-over > Syphon (siphon) 80% > Mocha > American drip 75-80% > Cupping 70-75% > French press 65-70%

Choosing Grind Size

Because different grind sizes correspond to different brewing methods, adjust the coffee grind size based on the equipment you're using. Below are the grinds from finest to coarsest and their corresponding brewing methods.

1. Turkish Coffee

This belongs to the ultra-fine grind category, with a texture similar to flour. Basically, it's the smallest setting on an espresso grinder - the smaller the number, the finer the grind.

2. Espresso (as shown above)

Espresso machines use 9 atmospheres of pressure to extract coffee compounds, also belonging to the extremely fine grind category. However, if you use a Turkish-level grind, it will clog the portafilter, preventing water flow and resulting in excessive extraction time. Therefore, you need to adjust to a coarser setting (higher number) for testing. Typically, single and double portafilters for espresso machines use 8-9g for single shots and 18-20g for double shots. Extracting 25-30g for single shots and 50-60g for double shots within 25-30 seconds is considered standard.

3. AeroPress (as shown below)

This is a piston-like extraction device where coffee liquid is pressed out by hand. Extraction time is about 2 minutes, but it's an immersion extraction method, so fine grounds can lead to over-extraction. Use a grind similar to pour-over coffee but adjust 1 to 1.5 settings coarser, falling into the medium-fine to fine category.

4. Siphon (as shown below)

Siphons use open flame to heat boiling water, which rises from the lower chamber to the upper chamber for immersion extraction. During this process, stirring is also performed. Fine grinding carries the risk of over-extraction, so medium grinding is necessary.

5. Pour-over Coffee (as shown below)

This is currently the most popular brewing method, but there are still many grind variations. It's often said that you should grind to a size similar to fine sugar, but many people don't understand that even with visual comparison, deviations can occur. Pour-over coffee uses a medium-fine grind, sized between fine sugar particles. The SCA recommends a sieve pass rate of 75-80%, which defines the standard grind size for pour-over coffee.

6. Moka Pot (as shown below)

The Moka pot is an ancient coffee device that extracts coffee in the upper chamber by heating water in the bottom until it boils. Previously, this was the primary method for making espresso-style coffee. The pressure is about 1.5 bar, so a relatively fine grind is needed, close to espresso grind but slightly coarser.

7. Cold Brew, Cold Drip

Both belong to long-duration, low-temperature immersion extraction, using ice water to slowly extract coffee flavor compounds. The extraction rate of ice water is very low, so long-duration immersion requires medium-coarse grinding. Medium-coarse grinding is easier to filter and won't cause gaps between grounds to be too fine, preventing water droplets from penetrating; cold brew also makes it easier to filter coffee grounds.

8. French Press (as shown above)

The French press is also an immersion extraction method, but unlike others, the coffee in a French press remains immersed throughout the process. Therefore, prolonged immersion can lead to over-extraction, making coarse grinding necessary. The grind size should be coarse, similar to larger particles like brown sugar.

The above are personal recommendations for coffee grind sizes and are for reference only. When you encounter problems during actual operation, adjust immediately rather than stubbornly adhering to a specific grind size. People have different tastes - some prefer lighter coffee, while others prefer stronger coffee. This is perfectly normal. What you think is just right might seem too strong or too weak to others. Don't let uncontrollable factors interfere.

Currently, the most commonly used pour-over grind sizes can be calibrated with sieves, so friends who need calibration can purchase one for this purpose. Next, it's time for brewing sharing! Let's brew Ethiopian Guji Buku using the standard pass rate defined by SCA and see what surprises await!

Example: FrontStreet Coffee's Ethiopia Buku Natural

• Region: Guji, Hambela
• Variety: Heirloom
• Altitude: 1800-2000 meters
• Processing: Natural

Pour-over Parameters

• Dripper: V60
• Water Temperature: 91°C
• Grind Size: Fine sugar (standard #20 sieve pass rate 80%)
• Water-to-Coffee Ratio: 1:15
• Technique: Three-stage extraction

Brewing: Use 30g of water for bloom for 30 seconds. In the second stage, slowly pour in circles to 120g, and after the water level drops to halfway, pour again to 225g and stop brewing. Wait for the coffee liquid to finish dripping, then remove the dripper. Total extraction time is 2:00-2:10 seconds.

Flavor Notes

Tropical fruits, mango, strawberry, passion fruit. Full and rounded acidity with solid mouthfeel.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473