Pour-Over Coffee | What Is the Purpose of Circular Pouring and How to Pour Correctly

The Art of Pour-Over Coffee: Exploring Circle Pouring Techniques

Have you tried pour-over coffee before? When you order pour-over coffee at a café, do you find yourself watching every move the barista makes? You want to learn their brewing techniques, and after watching them, you might say you understand how it's done, but when you try it yourself, your hands tell a different story—you really don't. Today, FrontStreet Coffee will explore the science behind circular pouring movements during brewing. Let's learn together!

Experimental Design

This experiment aims to investigate the impact of pouring speed in circular movements on coffee flavor. To ensure accurate results, we fixed the following brewing parameters:

• Coffee Dose: 15g
• Coffee-to-Water Ratio: 1:15
• Grind Size: 78% retention on #20 standard sieve
• Water Temperature: 90°C

For this experiment, we selected FrontStreet Coffee's Honduras Sherry beans, with the following details:

• Region: Marcala, Honduras
• Estate: Moca Estate
• Altitude: 1500-1700m
• Varieties: Caturra, Catuai, Pacas
• Processing: Fine washed with whiskey barrel fermentation
• Roast Level: Medium-light roast
• Flavor Notes: Vanilla, cream, fermented wine aroma, honey

Brewing Process

Fast Circular Pouring (1 second per circle):

Begin with 30g of water for a 30-second bloom. Pour at an average speed of 4g/s in circular movements from the center outward, then return to the center until reaching 125g. Pause until the coffee bed has dropped to half its height, then continue with coin-sized circular pouring until reaching 225g. Remove the filter once all coffee has dripped into the serving pot. Total brewing time: 1 minute 57 seconds.

Slow Circular Pouring (4 seconds per circle):

Begin with 30g of water for a 30-second bloom. Pour at an average speed of 4g/s in circular movements from the center outward, then return to the center until reaching 125g. Pause until the coffee bed has dropped to half its height, then continue with coin-sized circular pouring until reaching 225g. Remove the filter once all coffee has dripped into the serving pot. Total brewing time: 1 minute 57 seconds.

Experimental Results

Sensory Description

Fast Circular Pouring:

The wet aroma presents intense wine notes and vanilla. The flavor reveals rich dark cocoa and honey with a creamy mouthfeel.

Slow Circular Pouring:

The wet aroma shows noticeable wine notes and vanilla. The taste is relatively mild with brown sugar and chocolate flavors, subtle acidity, and a relatively thinner mouthfeel.

Conclusion

The speed of circular pouring during pour-over coffee brewing does indeed affect the coffee's flavor. When using fast circular pouring, water mobility increases, allowing maximum agitation of the coffee grounds, which enhances extraction yield. The resulting coffee becomes richer and more full-bodied with relatively abundant aroma retention.

Conversely, during slow circular pouring, only the force of the water stream itself scours the coffee bed. Some coffee grounds remain undisturbed in a static state, resulting in relatively lower extraction yield. The brewed coffee exhibits comparatively lacking mouthfeel and aroma, presenting an overall more balanced and gentle profile.