In the overcaffeinated competition among coffee makers, the AeroPress is a game-changer: an invention that thrills with its simplicity and functionality.

It makes extraordinary coffee – crisp, clean and balanced, allowing for the complex flavors of the ground beans to ring true on the palate without distracting bitterness.

What’s more, the AeroPress costs less than $30, is made of shatterproof plastic, is very easy to clean, was invented in California and, unlike nearly every other coffee contraption, is made in the United States.

William Glen, the prestigious gift and housewares shop at Town & Country Village, is among the local businesses that sell the AeroPress. “It consistently puts out good coffee,” said Rebecca Jarquin, who manages the coffee department. “The No. 1 reason we sell it is, we tried it. … If you try a cup of coffee from the AeroPress and you try a cup of coffee from a drip coffee maker, there’s just no comparison.”

The AeroPress has earned a fanatical following among the coffee-obsessed– along with a sip of controversy: Does it actually produce espresso or merely a very good cup of traditional coffee? The verdict: It can do both, though the small shots could be categorized as “espresso-like.”

Invented in 2004 by Alan Adler, a lecturer in mechanical engineering at Stanford University and a coffee fanatic, the AeroPress went to market in 2006. Sales started slowly, but the positive buzz among coffee geeks these days is worldwide. Adler said his family-run company has sold close to 500,000 units.

Sacramento’s Temple Coffee recently started selling the AeroPress and plans to conduct demonstrations soon at its two shops. Vaneli’s Coffee in Rocklin also sells it, and it’s available to order at a number of websites, including Amazon.com.

“The AeroPress has created this crazy following because it’s pretty simple to use,” said Sean Kohmescher, Temple’s owner. “It’s a great, fun tool at an inexpensive price.”

“If you’re right on with the water temperature and the pressure, it usually makes it perfect,” said Dave Whyte, Vaneli’s vice president of sales.

Though Kohmescher also likes French press coffee, in which coarse grounds are steeped in hot water for a few minutes, then pressed to the bottom of the pot, he said the AeroPress “presents a cleaner cup than a French press.”

The AeroPress has many prominent admirers, including Kenneth Davids, the coffee writer and taster who runs the website Coffee Review (www.coffeereview.com). Michael Phillips, the 2010 world barista champion, is also an AeroPress user, especially while traveling.

“I’m a pretty big fan,” said Phillips, the assistant director of education for Chicago-based Intelligentsia Coffee & Tea. “The main thing you are looking for in a proper cup of coffee is balance in the extraction. AeroPress does a really good job of doing this.”

The AeroPress method is distinct from other coffee makers, though it bears a resemblance to a French press. After a tiny circular paper filter is placed flat at the bottom of a plastic cylinder, ground coffee is poured on top of the filter. Hot water is added, and it is stirred for 10 seconds, then pushed with a sealed plunger, putting pressure on the coffee as the grounds are formed into a puck. The coffee comes out the bottom of the cylinder and into a cup after pushing for 20 seconds.

Adler said the AeroPress makes a more flavorful, less acidic cup than a French press because the paper filter reduces bitterness. The stirring, along with the finer grind used in an AeroPress, exposes more coffee – thus more flavor – to the water.

The AeroPress can make a double espresso or, by adding water after brewing, a full cup of coffee known as an Americano.

There is a vigorous debate as to whether the AeroPress makes legitimate espresso, the drink many consider the ultimate expression of a coffee’s flavor and complexity. Phillips and Kohmescher don’t consider the AeroPress shot a true espresso.

Said Adler: “Well-made espresso has a slightly different flavor than well-made AeroPress. Just because there is a difference doesn’t mean one is better than the other. The difference in espresso is a little bit of a bitter tang that is not in AeroPress.”

An excellent espresso requires a high degree of skill and a little luck, and it is not uncommon for baristas at the best coffee shops to pour out less-than-perfect extractions and start over. AeroPress shots of about 2-3 ounces, on the other hand, are relatively simple and consistent.

In tests at home, I made espresso-style shots using Hayes Valley Espresso beans from Bay Area-based Blue Bottle Coffee and Colombia Monserrate beans from Temple Coffee. (The Temple beans were recently rated an impressive 90 points by Coffee Review.) With the AeroPress, there was a sweetness to the shots and a wide range of flavor notes to both superb coffees that I did not experience in making espressos with a $1,000 espresso machine.

Coffee Review’s Davids, who lives in the Bay Area, took some heat when he initially praised the AeroPress and referred to its product as “espresso.” “The issue is with the way it messes with people with their coffee ideologies. It doesn’t fall neatly into any category other than AeroPress,” he said.

“I think it makes a very nice coffee, in part because it uses a pressure extraction that’s weaker than an espresso machine, and it has a paper filter which is dynamite. It has good body. It has some of the viscosity of espresso, but it doesn’t have the sediment that gets in almost every espresso.”

If you love coffee, you can easily become obsessed with the pursuit of the perfect pot. If you continue that pursuit, you will unofficially enter coffee geekdom, leading you to try the old-school Chemex maker, the moka pot, various kinds of espresso machines, vacuum pots and the simple and now-trendy Melitta-style “pour over” method – the way my mother has made her coffee for more than 30 years.

There are various opinions on what makes perfect coffee. In many cases, the process can be very complex and expensive. The AeroPress may be the simplest and cheapest way to approach coffee nirvana.

COFFEE TALK

Here’s how a simple, inexpensive device such as the AeroPress makes excellent coffee:

• The hot water is poured over the ground coffee, then stirred for 10 seconds, exposing all the coffee to the water. This does not happen with drip coffee makers.

• The small paper filter catches much of the acidity that gets through in methods with metal screen-type filters, including French press, espresso machines and the new $11,000 Clover machine recently introduced at select Starbucks locations.

• The pressure on the coffee from the plunging builds more flavor by making full use of the coffee. The manual “pour over” method, by contrast, leaves plenty of water behind with the used coffee grounds.