For serious coffee lovers every cup of should be perfectly fresh-brewed, but that's not always possible. In fact, it's a cruel irony that some mornings you might need a cup of coffee before you can successfully manage to brew a pot. Single-cup brewers address this problem, but at a high cost per cup. Instant coffee is a relatively inexpensive option, but its flavor is often disappointing. If you want fresh-coffee flavor with instant-coffee convenience, one alternative is to fine-grind your own.
Homemade "Instant" Coffee
A complex multi-stage industrial process that involves brewing regular coffee and then freeze-drying it is used to make almost all commercial instant coffees. While it’s not a practical option at home, another process is. It's possible to grind coffee so finely that its characteristic flavors and oils can be extracted almost immediately in hot water. This is essentially a high-speed version of what happens in a coffee brewer or drip cone. All you need is a practical way to reduce the size of your favorite ground coffee.
Quick and Dirty
If you have one of the small, inexpensive blade-type coffee grinders, that's ideal for the task at hand.
Measure a scoop or two of your regular ground coffee into the grinder.
Grind the coffee, alternating between pulsing and steady whizzing, until it begins to clump in the lower corners of the grinder.
Shake out the powdered coffee into a fine-mesh strainer or sifter. Sift the finest portion of the coffee into an airtight storage container.
Return the rest to the grinder and repeat, or just put it back into your can of coffee.
If you don't have a blade-type coffee grinder, you can use a blender, or even a mortar and pestle, to achieve a similar result.
The longer you grind the coffee, the more heat you'll generate through friction. Heat degrades the flavor of the coffee, so keep it brief. It's better to do several short, quick batches than one large, long one.
The Practical Details
Whole coffee beans have the longest storage life, while fine grinds oxidize and lose flavor most quickly because of their high percentage of surface area. Don't grind more than you'll use in a day or two, for the best flavor, and keep the powdered coffee in an airtight bag or container.
If you take your coffee in a restaurant-sized cup -- about 6 ounces -- you'll need roughly 1 1/2 tablespoons of the extra-fine coffee. In an 8- to 10-ounce mug, you'll need 2 tablespoons. If you like your coffee strong, err on the side of using more. You can always add extra water if it's too potent.
Measure the coffee into your cup.
Bring fresh, clean water to a boil in your kettle or a microwave oven.
Let it cool for 20 to 30 seconds, dropping below the boiling point, and then pour it over the powdered coffee grounds.
Stir the coffee thoroughly, then wait another 10 to 15 seconds before adding cream and sugar, if desired.
The grounds remain in your cup as you drink, and will gradually settle to the bottom. This means you won't want to slurp down that last mouthful of coffee, because it will be rather chewy. It'll also be strong and possibly bitter, because less-desirable flavors begin to appear as the grounds spend more time in contact with the water.
If you find you like coffee made this way, you'll get a more consistent result by investing in a higher-quality coffee grinder and a bag of whole beans. Modern burr-type grinders and vintage -- or reproduction -- hand-cranked grinders are capable of turning out a very fine grind indeed. It's traditionally used to make sweet, strong, frothy Turkish-style coffee, but it also works well for in-cup brewing. They can turn out coarser grinds for use in your regular coffee maker as well.