Peach jam is a type of preserved fruit made from both the juice of peaches and pieces of the fruit itself. A typical peach jam contains a large amount of sugar and is usually fortified with additional pectin. Jam can be safely stored for many months. Specialized versions of jam made from peaches exist for those on special diets and for those who must avoid sugar.
Making peach jam involves chopping up pieces of the peeled fruit and cooking them with water. Additional fruit juice is sometimes added to this mixture, either as a sweetener or to provide extra liquid and flavor. The quality and ripeness of the peaches used are important for both the flavor and color of the finished product. Bruised or unripe fruit will produce unappetizing jam.
Pectin is added as well, which causes the mixture to set into the thick gel-like consistency that is generally desired in jams and jellies. Some fruits, themselves, contain enough pectin to set without any additives. Peaches have little of their own, however, and generally need additional pectin to set properly.
Other additives may be included in peach jam. Commercial products may include them to preserve and enhance color or to further extend the shelf-life of the jam. Some varieties of jam may also include other fruits or spices to add flavor.
Jam made from peaches is placed into jars and exposed to high heat once again, usually with a hot water bath. This process kills microbes in the jam, ensuring that the jam will not spoil before the jars are opened. Sugar can aid in preservation because it can dehydrate the fruit and impede the growth of bacteria. The sugar in jam is not normally concentrated enough to serve this function, however.
Peach jam is normally very high in sugar, but low-sugar alternatives exist. The jam can be effectively sweetened with artificial sweeteners, and anyone making jam on their own should probably try small test batches with different sweeteners to determine which type they prefer. Home jam-makers should be careful when buying pectin for low-sugar jam, as some types of pectin require sugar in order to gel properly.
All-natural peach jam can be made with other sweet juices used in place of sugar. Pectin should generally be used, however, in order to ensure that the jam sets properly. Most pectin is produced from fruit, using a simple extraction process, and is not generally considered a chemical food additive.