The Basics: Auto-Drip Coffee Makers

Coffee makers come in a variety of different sizes, types and styles. One of the easiest to use and most versatile is the automatic-drip coffee maker.

Manufacturers have spent countless research dollars perfecting the brew mechanisms, adding sophisticated features and controls and otherwise improving their automatic-drip coffee makers. The result is a plethora of options, ranging from basic models to ultra-fancy top-of-the-line units.

For all of their sophistication, automatic-drip coffee makers are relatively simple devices, all of which function in a similar manner. Water is added to a tank or reservoir, where it is heated and then dispersed over a pre-filled basket of grounds. As the heated water travels through the grounds, it extracts flavor before it drips into a waiting container (i.e., mug, coffee pot or thermal carafe, or internal storage tank).

That being said, there's more than one way to brew a good cup of coffee. Factors such as the temperature of the water, the length of the brew cycle, the shape of the filter basket, and the way the water is dispersed into the filter basket all play important roles in the finished brew.

A second, but no less important consideration, is keeping the brewed coffee at the ideal serving temperature. Unless you are making a single cup or planning to consume the entire pot within a few minutes of brewing, you need a reliable way to keep the coffee warm until you are ready to drink it. Many automatic-drip coffee makers, therefore, feature built-in warming trays, designed specifically for keeping the brewed pot of coffee warm. Other models have eliminated the warming plate and replaced the traditional glass carafe with an insulated thermal carafe. Those models shut off immediately after brewing since the thermal carafes have their own heat-retaining ability.

A relatively new option in this category is the "coffee-on-demand" style machines. These units brew coffee directly into an internal holding tank where the coffee is kept hot and ready for dispensing one cup at a time. The coffee is dispensed by pressing your cup against a bar on the outside of the machine.

More than any other style, automatic-drip coffee makers offer a wealth of choices in terms of specialty features. Machines run the gamut from bare bones, no-nonsense models to fully loaded, turbocharged models that do everything from grinding the coffee to brewing it at a predetermined time.

Standard units consist of a power base, with water reservoir, filter holder, carafe and built-in warming plate or carafe stand. Most models have sensible dripless carafes, clearly marked easy-to-fill water reservoirs, swing-out or lift-out filter baskets, and simple, intuitive controls. Other features include indicator lights that signal when the unit is operating and when the brewed coffee is ready; cord storage, to cut down on counter clutter; and automatic shutoff.

A majority of models now have a brew-pause feature, which halts the flow of coffee long enough to pour a cup. Optional features include touchpad or digital control panels; clocks with timers to preset the start of coffee making; permanent gold-tone or screen filters, which replace the standard disposable paper filters; and automatic shut-off.

Fancier options in this category include built-in water filtration systems, which are designed to remove chlorine, bacteria and other contaminants from drinking water before brewing; flavor systems that can adjust the strength of the coffee--from mild to robust--to suit your taste; and built-in grinding, which allows you to add coffee beans, push a button and grind just prior to brewing for the freshest possible taste.

Another factor is size. Full-size auto-drip coffee makers usually brew up to 12 cups but can be set for smaller servings. Personal-size machines make up to four cups at a time and save counter space. Single-cup machines are available, which, in many cases, brew directly into a travel mug for convenient on-the-road coffee consumption.

All automatic-drip coffee makers require periodic cleaning or decalcifying to remove mineral deposits. This is accomplished by brewing a cycle with a special cleaning solution or a mixture of vinegar and water.

Automatic-drip coffee makers range in price from approximately $20 for a small capacity, basic unit to $300 for a full-size, top-of-the-line model, loaded with specialty features.

Coffee makers usually carry 1- or 2-year warranties. Higher-end units are backed by slightly longer warranties.

How to Shop

Because of the popularity of automatic-drip coffee makers, manufacturers have leapt to the challenge of creating the perfect machine for every household. By producing more and more models, however, they have saturated the market with machines in every conceivable size, style and color available. While this is good news for the consumer, shoppers may find themselves in a quandary over which model to purchase.

Before you go shopping, consider these factors:

How often will you use the machine?
Many coffee devotees brew at least one pot every day, usually first thing in the morning. Others brew frequently throughout the day. If you plan to use your machine daily, it pays to invest in a model with durable construction. Because much of the "wear and tear" occurs through leaving the unit in the "on" position so that the warming tray can operate, you might consider buying a machine with a thermal carafe, or investing in a free-standing carafe and pouring the coffee into the carafe immediately after brewing.

If you are more of a weekend coffee drinker, wear and tear is less of an issue, however you still want a machine that is reliable and convenient to use.

How many cups do you routinely brew?
Size matters with automatic-drip coffee makers. Full-size machines perform best when set to brew a full pot of coffee. These machines offer the advantage of preprogrammed brewing technology, which times the distribution of heated water through the grounds for optimum flavor extraction. A full pot usually consists of 8-14 cups and takes anywhere from 5-12 minutes to complete the brew cycle.

In coffee maker lingo, a "cup" of coffee refers to a portion equal to approximately 5-6 ounces, not the standard 8 ounces in a traditional cup measurement. So, a machine that brews eight cups actually makes enough coffee to dispense about six standard coffee cups or four decent sized mugs. Although coffee strength is a matter of personal preference, the recommended amount of ground coffee is approximately 1-2 tablespoons for each brewed 5-ounce cup.

If you regularly brew only 2-3 cups of coffee, doing so in a large machine can result in flavor loss, as the grounds are spread over a wider area and the heated water does not have time to extract the full flavor. Smaller machines are available and some full-size machines offer a 1- to 4-cup feature to compensate for the smaller quantity of grounds. The feature lengthens the brew time to allow full flavor extraction with smaller batches.

Which specialty features do you need?
By far the most common specialty feature available on auto-drip coffee makers is a digital clock/timer, which allows you to preset the time of brewing. This feature, which is almost exclusive to auto-drip machines (and one of the main reasons for their popularity), offers the advantage of set-it-and-forget-it operation since you can literally add the water and ground coffee the night before and awaken to a freshly brewed pot of coffee.

Another optional feature is water filtration, usually in the form of a charcoal insert that removes many of the impurities in tap water, including chlorine. Filters can not only improve the taste of the coffee but also can preserve the life of the coffee maker by preventing calcification buildup. The filters have a limited lifespan, usually around two months or 60 uses.

More and more manufacturers are offering a brew-through thermal carafe in place of the traditional glass carafe. These insulated carafes can be removed for serving, yet they still retain the heat and flavor of freshly brewed coffee. These models also save energy by shutting themselves off immediately after brewing.

One of the newest offerings is the coffee-on-demand style machine. These models do not have carafes. Instead, the coffee is brewed directly into an internal tank where it is kept hot and ready for dispensing.