(MONEY Magazine) – Apparently, a Starbucks on every corner is not enough. Americans want espresso, and they want it at home. One in 10 households has an espresso maker, according to a recent survey by the National Coffee Association, up from just 1% in the mid-1990s. Unfortunately, many of those appliances are destined to languish, unused, in remote corners of kitchen cabinets, right next to the dust-laden fondue pots. The reason: Many of the most popular models produce a lousy imitation of espresso, and they're a pain to use.

Home espresso makers that conquer both drawbacks exist. Yet one problem remains: Prices range from $30 to more than $1,000. So which of the baffling array of features do you need, and which are just froth? Determined to answer those questions, we got in touch with Andrea Illy, chairman of Illycaffe, the coffee company started by his grandfather in Trieste, Italy in 1933. Illy, a chemist whose thesis was called "The Quality of Espresso from a Chemical Perspective," agreed to meet us for a cup of espresso and a shot of his expertise.

Expertly swirling his drink around a demitasse to gather up the precious crema--the thin layer of tiny, flavor-rich bubbles that tops a good espresso--Illy explains that the only way to make real espresso ("the kind made in Italy") is to force water that's just shy of boiling through compressed espresso grounds at high pressure. Properly done, this leaves behind the bitter flavors you don't want and delivers "the quintessence of coffee."

Most cheap espresso makers, however, fail on two accounts. First, they use steam to force water through the grounds, and steam, Illy maintains, simply can't generate enough pressure. Second, a steam-driven machine makes the water too hot, destroying the natural oils that carry good flavors (and, ideally, emulsify into crema) and effectively burning the coffee.

The solution is a pump, which creates sufficient pressure without the aid of steam and therefore lets the water remain below boiling. To keep the water at the ideal temperature of 190 [degrees] F to 196 [degrees] F, a machine should also have a heat regulator. You can buy an espresso maker with those two essential features, such as the Espresso Gaggia or the Starbucks Barista (pictured below), for between $150 and $250.

Neither the regulator nor the pump is visible from the outside, so check the machine's specifications. Also, eye the water compartment. On a pump machine, you pour water into an unsealed compartment, like the one on a drip coffeemaker; a steam-driven machine, on the other hand, can be easily identified by the airtight, screw-on lid on its water compartment, which is necessary for building up pressure.

HOLD THE FROTH

Believe it or not, Illy insists, nothing else besides quality beans is necessary to make first-rate espresso. The rest of the features make the process faster and less labor-intensive, but they offer diminishing returns as the price goes up. For example, while most machines have a wand that shoots steam into a pitcher of milk, others steam the milk internally and then release it at the touch of a button. That's nice, but some of the time that's saved is lost on the additional internal cleaning. Ditto for expensive machines that grind, measure and compress the coffee. As with owning an exotic sports car, what's a pleasure to use may require you to keep a mechanic on hand. Even sillier is the so-called two-way solenoid valve, which whisks away the water left in the grounds. Only professional espresso makers truly need this feature.

DAILY GRIND

For our money, the most cost-effective, effort-saving feature available is a filter holder that accommodates a new, standardized prepackaged espresso format called Easy Serving Espresso (ESE). To brew a cup of espresso, all you do is put an ESE "pod" in your machine's filter holder and press START. Gone is the cumbersome process of grinding, measuring and compressing the grounds--as well as the messy cleanup afterward.

Other prepackaged espresso formats exist, but ESE seems to be the burgeoning standard: More than 20 bean roasters and machine makers, including industry giant Krups, have signed on since its creator, Illycaffe, started licensing the system for free in February. Although the ability to handle ESE pods adds almost nothing to the cost of the machine, the pods run between 50[cents] and 75[cents] a serving. The $150 Espresso Gaggia machine comes pod-compatible if you order it through Illycaffe (888-322-4559); the Starbucks Barista, which sells for $250 ($300 for a stainless-steel body), can be ESE-equipped as well. Starbucks and other gourmet stores sell the pods, or you can order them by mail from Illycaffe or Williams-Sonoma (800-541-2233).

Finally, you can consider looks. But aside from aesthetics, the only advantage of a metal body is that you can store your cups on top, warming them the way restaurants do. With the right machine, however, you can forgo another restaurant touch: that lemon peel served on the side. "Strictly forbidden," says Illy, claiming the practice was invented to mask the taste of poorly made espresso. "If the coffee is good, you don't need lemon; and if the coffee is not good, it's better not to drink it."