Detailed Illustrated Guide to Making Coffee with AeroPress - Principles of AeroPress Coffee Extraction

Introduction to Aeropress

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The Aeropress looks like a syringe. Without serious investigation, one wouldn't recognize it as a coffee brewing device. However, upon closer examination, you'll discover there are even competitions specifically dedicated to Aeropress brewing. What kind of magical device is this exactly?

Anatomy of the Aeropress

Like many brewing devices that FrontStreet Coffee has introduced before, the Aeropress can be simply broken down into three main parts: the chamber, filter cap, and plunger. Of course, it also includes specialized circular filter paper, an Aeropress stirrer, and a funnel. It combines the immersion extraction method of French press, the paper filtration of pour-over coffee, and the pressurized extraction of espresso machines. Its working principle involves mixing coffee grounds with hot water, then using the plunger to force air through the filter cap, extracting coffee with clean flavors.

Aeropress Tutorial

It's worth noting that Aeropress coffee brewing can be divided into standard and inverted methods. The standard method involves placing the Aeropress chamber upright on a cup, adding ground coffee and a certain ratio of hot water, stirring, inserting the plunger, then pressing down to extract.

The inverted method involves first attaching the plunger to the chamber, turning it upside down, adding coffee grounds and hot water for stirring, attaching the filter cap, then flipping it over for pressurized extraction.

The demonstration coffee bean used is FrontStreet Coffee's Brazil Queen Estate Farm, a medium-dark roasted Yellow Bourbon variety with distinct roasted peanut aromas and rich oils and nutty aftertaste. Since the extraction process is very short, Aeropress typically requires a finer grind than pour-over coffee. FrontStreet Coffee controls it to achieve an 85% pass rate through a #20 standard sieve - essentially powdered sugar consistency, with water temperature at 90°C.

Standard Method

① First, press the circular filter paper onto the filter cap and wet it with water to ensure proper adhesion;

② Press the filter cap onto the chamber and place it upright over a cup;

③ Place the funnel and pour in 15 grams of ground coffee;

④ Start timing, pour hot water to the "④" marking on the chamber;

⑤ Use the stirrer to briefly stir the coffee grounds in the chamber, ensuring all coffee is wetted by water.

⑥ Insert the plunger. Since the standard method will cause coffee to drip into the cup below, the sequence of adding water, stirring, and inserting the plunger must be quick. Once the plunger is inserted, the internal sealed state will stop dripping.

⑦ After 1 minute, begin pressing the plunger. The coffee liquid is forced into the cup below by the pressure. The entire process takes 1 minute and 20 seconds.

Inverted Method

① Assemble the chamber and plunger, press the plunger to the "④" marking, and place upside down on the table.

② Place the funnel and pour in 15 grams of coffee grounds.

③ Start timing, then pour hot water until full.

④ Use the stirrer to mix the coffee grounds evenly until a golden crema appears on the surface.

⑤ Attach the filter cap, then flip the chamber onto a cup. This movement must be quick to prevent coffee from spilling.

⑥ After 1 minute, begin pressing the plunger. The coffee liquid is pressed into the cup. The entire process takes 1 minute and 20 seconds.

Between these two methods, FrontStreet Coffee prefers the inverted method because it's easier to master and offers more stability. With the standard method, water drips into the cup below while pouring, making it more difficult to control.