Water

Rule of Thumb: Water is 98% of your cup; if it doesn't taste good from the tap, don't brew with it.

Hard v. Soft:

"Hard" water is alkaline water and though the basic nature does not harm flavor or aroma, it will neutralize some of the natural acids in your coffee and you will end up with a blander brew. It is generally agreed that water containing 50 to 100 parts per million of dissolved minerals will produce the best tasting coffee.

But extra hard water doesn't mean you should soften it; the other extreme is just as bad. Softeners tend to slow the coffee-extraction process in most brewers, thus weakening the ultimate quality of your coffee. Our advice to people with hard water: either use bottled or filtered water, or stick to extra-acidic beans like those from Africa, Arabia, and the higher quality products from Central America.

Distilled water, the ultimate in soft water, has been stripped of all minerals - Please don't use distilled water to make regular coffee (espresso is, as always, a different story). It will NOT produce the cup you are trying so hard to achiev

In general, it's a great idea to get a filter. The cheapest way to go is the pitcher filter (Brita, PUR, etc.), a refrigerator-stored plastic pitcher with a charcoal filter. Of course, you need to remember to change the filter every two months or so and to clean the darn thing even more often.

More expensive but more convenient is the "faucet dongle" design which gloms on to your kitchen faucet at something of a price aesthetically-speaking. (Also available from Brita and PUR among others.)

We think the best way to go is the under-the-counter dual-stage variety -- two cartridges work together to filter out chemicals, heavy metals, and mysterious organic material. Though you still have to remember to change filters every now and then, it's worth the trouble. We like a design by Plymouth Products.

Important note: If you are brewing espresso, you are simply NOT allowed to leave your water unfiltered. Whereas the effect of water on regular coffee can often be merely a question of taste, the combination of hard water and espresso brewers verges on criminal. (well, not really.) With espresso, soft water is suddenly okay, even recommended! (It doesn't affect brew quality, and is easier on the delicate parts of your machine.)

It's all very confusing, we know. And you haven't even had your coffee yet!