The Origin Story of the Clever Dripper - Introduction to Clever Dripper's Structure, Principles, and Brewing Process with Immersion Time

Introduction to the Clever Coffee Dripper

The Clever Coffee Dripper is a coffee filtration device invented by Taiwan's EK INTL company. The bottom of the dripper features a controllable switch valve that allows free adjustment of the extraction's immersion duration. It's convenient and easy to use, which is why it's named "Clever." Many filter cups with switch valves on the market are sold by merchants under the name "Clever," but in principle, only those sold under the Mr. Clever brand can be called "Clever Coffee Drippers."

Design and Functionality

The design inspiration for the Clever Coffee Dripper comes from another product by EK INTL company used for brewing tea—the HandyBrew. Immersion extraction is its greatest highlight. The Clever Coffee Dripper typically consists of inner and outer layers—the outer layer is a frame that supports the filter cup, while the inner layer is the cup body with a press-style switch valve. When placed flat on a table surface, the valve remains in a closed state, preventing coffee liquid from flowing down, keeping the coffee grounds and water in an immersion state. When the immersion is complete, the middle of the base receives pressure, prompting the piston valve to open and allowing the coffee liquid to flow into the container.

Immersion vs. Drip Extraction

Compared to direct drip-style filter cups like the V60, the Clever Coffee Dripper adds the functionality of immersion extraction, which allows water and coffee grounds to maintain continuous contact within the container. Immersion extraction is less affected by pouring techniques, making it easier for beginners to replicate the basic flavors of coffee. Flavor compounds change the coffee's flavor and concentration based on water temperature, coffee-to-water ratio, grind size, and immersion duration.

Like brewing coffee with filter cups and filter paper, when using the Clever Coffee Dripper for the same coffee beans under identical water temperature, coffee-to-water ratio, and extraction time, if the grind is too coarse, the coffee flavor tends to be under-extracted, resulting in flat flavors lacking complexity. If the grind is too fine, the coffee flavor tends to be over-extracted—meaning after the flavor compounds are extracted, the coffee grounds continue to contact hot water, releasing woody and other unpleasant flavors, resulting in strong coffee flavor with undesirable notes.

Brewing Recommendations

FrontStreet Coffee suggests using medium-fine grind (75%-80% pass-through rate on standard #20 sieve) for medium-light roast coffee beans when brewing with the Clever Coffee Dripper; for medium-dark roast coffee beans, use medium-coarse grind (65%-70% pass-through rate on standard #20 sieve).

If the water temperature is too high, the coffee flavor will release too quickly, leading to over-extraction. If the water temperature is too low, the coffee flavor release slows down, leading to under-extraction. FrontStreet Coffee suggests using 90℃-91℃ for medium-light roast coffee beans when brewing with the Clever Coffee Dripper; use 88℃-89℃ for medium-dark roast coffee beans.

Coffee-to-Water Ratio

Based on SCA Golden Cup extraction standards, FrontStreet Coffee conducted brewing experiments using different coffee-to-water ratios and filter cups, discovering that using a 1:15 ratio results in extraction yields of approximately 17.79%-18.73%. Although this is just at the edge of meeting the Golden Cup standards, sensory testing revealed that the flavors are very suitable and adaptable for brewing the vast majority of coffee beans.

Brewing Demonstration

Next, FrontStreet Coffee will use Costa Rica Piedra Negra Blueberry coffee beans for a brewing demonstration. Water temperature: 90℃, Coffee amount: 15g, Coffee-to-water ratio: 1:15, Grind size: Medium-fine (75% pass-through rate on Chinese standard #20 sieve).

1. Fold the filter paper and place it in the Clever Coffee Dripper. Place the Clever Coffee Dripper on a container and rinse the filter paper with hot water while simultaneously preheating the equipment.
2. Move the Clever Coffee Dripper to the electronic scale (the valve will automatically close at this time). Pour the ground coffee into the center of the filter cup. For the first pour, inject 30g of hot water, start the timer, and bloom for 30 seconds. After blooming, inject hot water to 225g, then immerse for 1'50".

After immersion is complete, move the Clever Coffee Dripper to the container and open the valve to filter the coffee liquid from the filter cup. The entire process takes approximately 15 seconds, with a total coffee extraction time of 2'05".

Due to immersion extraction, the coffee concentration can be adjusted according to personal preference by changing the coffee-to-water ratio or immersion duration. Coffee brewed with the Clever Coffee Dripper has high clarity, good body, and rounded sweetness.

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat public account: cafe_style).

For more specialty coffee beans, please add FrontStreet Coffee on private WeChat (FrontStreet Coffee), WeChat ID: qjcoffeex

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473