Instant coffee isn't usually the first thing you think of when you are talking about finely brewed coffee. Generally, instant coffee is considered a poorer form of coffee, used out of convenience rather than quality. What exactly is in instant coffee, and how is the stuff made?
Though it may seem like an artificial product, instant coffee crystals are nothing but coffee that has been dried. There are no extra chemicals or additives. Different manufacturers use different methods to create the dry crystals, usually either spray-drying or freeze-drying. The freeze-drying process will produce better quality instant coffee that tastes more like the "real" thing. Freeze-dried coffee is first brewed into the usual liquid form, and then it's flash frozen. The water is allowed to sublimate out (like evaporation, only with solid ice) in a vacuum chamber, and all that remains is dry crystals of pure coffee.
The other type is made by using a fine nozzle to spray liquid coffee into a large open chamber filled with dry warm air. The tiny droplets quickly dry and form very small particles of dry coffee. This actually produces a powder that can be harder to dissolve in water than the crystals. So this type of product is processed further to clump up the powder into the granulated crystals you find in the stores. Even with the extra step, this is the quicker way to manufacture instant coffee and the final product is usually cheaper. Either way, all you need to do to reconstitute the coffee is add hot water with a teaspoon or two of crystals. It's virtually impossible to make any mistakes, which is why instant coffee is still a popular product. Instant coffee is particularly popular during the summer months when people are making iced coffee drinks.
It's much more pleasant in a hot kitchen to be able to make a drink without having to add more heat to the room. The crystals do dissolve better in hot water, but a little extra stirring lets you make an iced coffee without any hassle. These days, not all instant coffee comes in crystal form though. A few new innovations have added a new dimension to instant options. You can now get a few different types of liquid instant coffee that gives a much better cup of coffee in the end. They are usually labeled as a "coffee extract" or "coffee concentrate" but the idea is the same. You just add hot water, and you've got a cup of coffee.
Java Juice is one brand, and they carry a couple of flavored coffees as well as a decaf version along with their original blend. The packages resemble the little packets of ketchup you get at a fast-food place. You just snip off the end and squeeze out the extract. They are typically sold in individual units, unlike the large jars you get of the crystals.