There are two principal means of brewing coffee: infusion and decoction. Infusion involves extracting the flavor from the grounds by using a liquid that is below the boiling point; with the decoction method, the liquid is allowed to boil.

One can choose from an impressive assortment of coffeemakers -- drip models, vacuum pots, extractors. It's useful to remember that many connoisseurs favor some form of the drip method, and that not one will defend the familiar percolator, which overextracts the coffee ground, overheats the coffee and creates a bitter brew. When considering a given system, it's smart to look at factors like volume, durability, ease of operation and cleaning, and even the warranty on equipment that you're looking at. Don't be lured into investing in a coffeemaker that looks good but produces a bigger pot than you need.

Be sure to select the grind best suited to the system you settle on; the finer the grind the more rapidly the grounds will be extracted. Coarser grinds are suited to longer brewing cycles; drip pots require a fine or medium grind.

There are a few hard-and-fast brewing rules. Namely:

Keep your equipment spanking clean. Wash or rinse it every time you polish off a pot; be sure to use only hot water or a special pot-cleaning solution (never soap or abrasive cleaners).

Use the best water you can get. Brew with bottled spring water if the version that comes from your tap has a nasty taste. Never use artificially softened water, and avoid hard stuff. Always begin with water that is very cold and freshly drawn; the sort that lurks in the hot-water pipes is often stale and flat.

Brew coffee at a temperature suited to your brewing method: That means using boiling (not near-boiling) water for a drip or plunge pot.

Measure carefully: Use the right proportion of water to coffee. A good guide is two level teaspoons of coffee for each six ounces of water. If you want a less strong concoction, add boiling water to the final product rather than skimping on the grounds.

Brew for the proper length of time. For a regular grind, this means six to eight minutes; with the drip method, four to six minutes. Fine grinds require four minutes or less.

Other secrets of success:

If you make less than three-three-fourths of the capacity of your coffeemaker, you'll be wasting some of the grounds. (Invest in a small pot if your old one is too capacious.)

Try not to reheat coffee; if you must, heat it over a low flame and don't allow it to boil. To keep it warm and fresh, store it in an insulated thermos.

Never reuse coffee grounds.

Avoid metal coffee pots, which can impart a metallic taste to the final product.

Cora and Mrs. Olson notwithstanding, the mass-market coffees that you find at the supermarket are generally more trouble than they're worth. They're chock full of low-quality Robusta beans; not one has a healthy proportion of the choice Arabica variety. This means that even when perfectly prepared, they can't even touch the full flavor of the whole-bean specialty coffees.

Small shops that specialize in wholebean Arabics are the most likely sources for first-rate beans. It's a joy to encounter their foreign exotica: Celebes Kalossi, Sumatra Mandehling and the like. The only problem is that it's not uncommon for some of these stores deliberately to mislabel their merchandise and charge premium prices for inferior goods. It pays to know the characteristics you're looking for. Consult a reliable tome or two: "The Signet Book of Coffee and Tea," by Peter Quinn, is good; so is "The Book of Coffee and Tea," by Joel, David and Karl Schapira.

Generally, the surface of a coffee bean should look shiny and rather greasy. A dry-looking surface usually indicates an overaged bean. Dark-roasted coffees will look mottled; light roasts will show less oil on the surface. One good way to test a bean's mettle is to bite it. Fresh ones are brittle and flavorful, while a too-old bean is rubbery and hard.

The infinte number of fine coffees vary in acidity, aroma, flavor and body and are available in a spectrum of grades, roasts and types. The best way for a beginner to become acquainted with various coffees is to scout out the specialty stores. Find a knowledgeable, trustworthy shopkeeper and latch on to him. For starters, try the house blend at a shop you're fond of. Experiment with tastes; compare roasts. Look for a store that roasts its beans right on the premises; the quality and freshness of the beans is likely to be superior there.

Watch the labeling in specialty stores. Beware of coffees that are presented as Jamaican; only an infinitesimal amount of the coffee grown in Jamaica is imported into the United States. Also beware of other beans labeled as very rare varieties: It could be that your favorite store has just latched onto scarce varieties, or it could be that someone is trying to sell you something he doesn't have. Most important, comparison shop.

When you've settled on a particular coffee, buy only as much as you'll consume in a week. Beans begin to get stale within one to three weeks after they are roasted. If you purchase beans at their peak of flavor, store them in a glass jar or other airtight container and place them in the refrigerator.

Although you can get most shops to grind your beans on the premises, it's a good idea to bring them home intact; whole beans stay fresh far longer than ground coffee, particularly if they are kept in the freezer.