About the AEROPRESS Coffee Maker
AEROPRESS is the result of several years of applied research by inventor/engineer Alan Adler. He conducted numerous brewing experiments, measuring the brew with laboratory instruments. The experiments demonstrated that proper temperature, total immersion, and rapid filtering were key to flavour excellence. He then designed and tested dozens of brewers before settling on the AEROPRESS design. The design was further validated by coffee lovers who tested prototypes in their homes. Adler has about forty U.S. patents and an equal number of foreign patents. He is President of Aerobie, Inc., in Palo Alto, California, and is a lecturer in mechanical engineering at Stanford University. Adler's best-known invention is the Aerobie flying ring, which set the Guinness World record for the world's farthest throw (1,333 feet).
How does the AEROPRESS work?
The AEROPRESS is an entirely new way to make coffee. It works like this:
- Water and grounds are mixed for ten seconds.
- Then gentle air pressure pushes the mix through a micro-filter in 20 seconds.
- The total brewing time of only 30 seconds results in exceptionally smooth flavour.
- Many tasters, including professional cuppers, have praised the smooth, rich flavour.
There are several reasons why AeroPress coffee tastes so good:
- Total immersion of the grounds in the water results in rapid yet robust extraction of flavour.
- Total immersion permits extraction at a moderate temperature, resulting in a smoother brew.
- Air pressure shortens filtering time to 20 seconds. This avoids the bitterness sometimes resulting from longer processes like drip brewing.
- The air pressure also gently squeezes the last goodness from the grounds, further enriching the flavour.
- Because of the lower temperature and short brew time, the acid level of the brew is much lower than conventional brewers. Laboratory pH testing measured AEROPRESS brew's acid as less than one fifth that of regular drip brew. The low acid is confirmed by coffee lovers who report that AEROPRESS brew is friendlier to their stomachs.
AEROPRESS compared with Drip Brewing
Drip brewing passes water through a bed of grounds. When the water first drips into the bed, it is too hot, and bitterness is extracted. As the water filters downward through the bed, it becomes too cool, and extraction is weak. Water also doesn't contact all of the grounds uniformly. Grounds at the edge of the bed are under-extracted while grounds at the centre are over-extracted and contribute bitterness. The lengthy wet time of drip brewing also extracts bitterness from the grounds.
Total immersion of the grounds in the AEROPRESS completely solves these problems. All of the grounds contact the same water temperature, and the brewing process is short and sweet. The gentle air pressure of the AEROPRESS also extracts extra flavour from the coffee. Ordinary drip brewers leave a lot of flavour in their soggy grounds.
The drip method cannot make a robust single cup because the small amount of water doesn't heat the bed enough for rich extraction. It is also slow. AEROPRESS makes one to four servings with a single pressing in less than a minute. The flavour is equally rich for any number of cups. Finally, drip brewers cannot make espresso or lattes.
AEROPRESS compared with Espresso Machines
Most coffee lovers agree that espresso is less bitter than drip brew because of the shorter brewing time. However, when we ran comparison taste-tests in the homes of espresso lovers, they all agreed that AEROPRESS espresso tasted better than the brew from their high-priced European espresso machines -- why? The reason is that the total immersion brewing of the AEROPRESS yields a robust flavour at a lower temperature -- and lower temperature brew is far less bitter.
Home espresso machines don't allow adjustment of temperature. But even if they did, their lack of total immersion would not yield robust flavour at reduced temperature. In addition to smoother taste, the AEROPRESS has several other advantages over conventional espresso machines:
- Grind is not critical in the AEROPRESS. Grind is so critical for espresso machines that most grinders cannot produce a grind fine enough to make a good-tasting shot! Special espresso grinders cost hundreds of dollars and require frequent cleaning. Also, expert baristas always adjust the grind when there are changes in humidity or batches of coffee. They throw away two or three shots while adjusting the grind in to achieve the right shot.
- There is no tamping in the AEROPRESS. Espresso instruction teaches the art of applying just the right amount of tamping. They instruct the home barista to practice on the bathroom scale to learn exactly thirty pounds of pressure.
- There is no pre-warming of the portafilter head. In fact, the AEROPRESS has no portafilter head!
- There is no maintenance. Espresso machines require regular cleaning and descaling with caustic chemicals. They also require dis-assembly and cleaning of the showerhead.
- There is no need to judge when to stop the pull. This is the most critical skill in using an espresso machine. As espresso lovers well know, most would-be baristas in coffee shops, hotels, and restaurants run the pump too long -- extracting sour bitterness from the grounds.
- With the AeroPress, the amount of water is predetermined by the user, who can brew any strength from weak to super-intense just by choosing the desired amount of water prior to pressing.
AEROPRESS compared with French Presses
People see some similarities between the AEROPRESS and a French Press. Both use total immersion and pressure. But the similarities end there. The filter in the French Press is at the top of the mixture. Because coffee floats, the floating grounds clog the filter and makes pressing and cleaning very difficult. Users are instructed to use only coarse ground coffee. But this reduces the amount of flavour that can be extracted from the coffee and necessitates long steeping times that extract bitterness. Furthermore, even coarse ground coffee includes many fine particles. These small particles pass through and around the filter resulting in a bitter, gritty brew. The particles in the brew continue to leach out the bitterness. Consequently, French press users are advised to drink or decant the brew immediately. Also, some particles clog the filter screen, making pressing and cleaning very difficult.
AEROPRESS coffee is micro-filtered. It so pure and particle-free that it can be stored for days as a concentrate. The concentrate can be drunk as espresso, mixed with milk for lattes, or diluted to make American coffee. French presses cannot make espresso or lattes. Finally, cleaning the French press is quite a chore. The AEROPRESS chamber is self-cleaning. A ten-second rinse of the plunger is all that's required.