There are several ways to bottle juices without using preservatives. Some people believe that preservatives are harmful, or that the treatment processes used to create a juice with a long shelf life are bad for the juice. It is certainly true that extensive pasteurization of juices can degrade its nutritional value, as heat has been known to reduce the content of some dietary vitamins and minerals. Juices produced without preservatives are perfectly safe to consume, as long as stipulations about expiration dates are observed.
While people say that a juice has been bottled without using preservatives, this term is actually a bit deceptive. Most juice companies mean that the juice has been bottled without the use of artificial preservatives such as chemicals. There are plenty of natural preservatives in the world, however, including cranberry juice, lemon juice, and many others. Commonly, a juice producer includes these naturally preservative juices in a blend to extend its shelf life. This allows them to say that a juice has no preservatives, since they are simply part of the juice blend.
The inclusion of natural preservatives in a juice can keep it shelf stable for several months, often at room temperature. These juices must generally be refrigerated after they have been opened, and some start to deteriorate after opening, so finishing them quickly is recommended. When purchasing natural juice without artificial preservatives in the store, shoppers should always check to be sure that the juice is tightly sealed; if the lid is concave, it means that the bottle of juice may be contaminated. Consumers should look for convex lids and not be too worried about sediment in the juice, as this is common with natural juices.
In other cases, a juice may be deliberately designed with a short shelf life. Such juices are typically subjected to a flash pasteurization process that quickly heats the juice to kill any unwanted organisms, and they must be kept under refrigeration to stay fresh. The juice will generally keep around a week under proper refrigeration. Orange juice is often sold this way, since companies expect consumers to be able to finish it fairly quickly.
People who want to make juices at home can read up on natural preservatives and juice making in general. Many home-made juices can keep for several months if they are handled well and kept in sterile containers.