Instant coffee is a beverage derived from coffee. Through various manufacturing processes the coffee is dehydrated into the form of either powder or granules. These can be rehydrated using hot or boiling water to provide a drink that most people are happy to accept as 'coffee'. There is also at least one brand of instant coffee available in concentrated liquid form. The advantages of instant coffee are speed of preparation (no time is required for infusing the coffee – it is ready as soon as the hot water is added) and long shelf life (natural coffee, especially in ground form, loses flavor as its essential oils evaporate over time. The disadvantages are that instant coffee is easily spoiled if not kept dry and its taste, especially with cheaper brands, is often far from the real thing.