Fruit jellies are semisolid, preserved mixtures of fruit juice and sugar. Jelly making is a good way to preserve fruit flavors for enjoyment throughout the year. Fruit jelly is a fairly easy-to-prepare product for the beginning canner and may be made at home without much special equipment.
Substances essential for fruit jelly making are fruit flavor, pectin, sugar, acid and water. A pectin gel or jelly forms when a suitable concentration of pectin, sugar, acid, and water is achieved.
The Manufacturing Process
The ingredients must be added in carefully measured amounts. Ideally, they should be combined in the following manner: 1% pectin, 65% sugar, and an acid concentration of pH 3.1. Too much pectin will make the spread too hard, too much sugar will make it too sticky.
- 1 When the fruit arrives at the plant, it is inspected for quality, using color, ripeness, and taste as guides. Fruit that passes inspection is loaded into a funnel-shaped hopper that carries the fruit into pipes for cleaning and crushing.
Cleaning, crushing, and chopping
- 2 As the fruit travels through the pipes, a gentle water spray clears away surface dirt. Depending on whether the finished product is to be jam or jelly, paddles push the fruit and or just its juice through small holes, leaving stems and any other excess debris behind. Some fruits, such as citrus and apples may be manually peeled, cored, sliced and diced. Cherries may be soaked and then pitted before being crushed.
Pasteurizing the fruit
- 3 The fruit and/or juice continues through another set of pipes to cooking vats. Here, it is heated to just below the boiling point (212° F [100° C]) and then immediately chilled to just below freezing (32° F [0° C]). This process, pasteurization, prevents spoilage. For jelly, the pulp is forced through another set of small openings that holds back seeds and skin. It will often then be passed through a dejuicer or filter. The juice or fruit is transferred to large refrigerated tanks and then pumped to cooking kettles as needed.
Cooking the jam and jelly
- 5 Premeasured amounts of fruit and/or juice, sugar, and pectin are blended in industrial cooking kettles. The mixtures are usually cooked and cooled three times. If additional flavorings are to be included, they are added at this point. When the mixture reaches the predetermined thickness and sweetness, it is pumped to filling machines.
Filling the jars
- 6 Presterilized jars move along a conveyer belt as spouts positioned above pour premeasured amounts of jam or jelly into them.
Metal caps are then vacuumed sealed on top. The process of filling the jars and vacuum packing them forces all of the air out of the jars further insuring the sterility of the product.
Labeling and packaging
- 7 The sealed jars are conveyed to a machine that affix preprinted labels. According to law, these labels must list truthful and specific information about the contents. The jars are then packed into cartons for shipment. Depending on the size of the producer’s operation, labeling and packaging is either achieved mechanically or manually.
In the United States, food processing regulations require than jams and jellies are made with 45 parts fruit or juice to 55 parts sugar. The federal Food and Drug Administration (FDA) mandates that all heat-processed canned foods must be free of live microorganisms. Therefore, processing plants keep detailed lists of cooking times and temperatures, which are checked periodically by the FDA.
Requirements also exist for the cleanliness of the workplace and workers. Producers install numerous quality control checks at all points in the preparation process, testing for taste, color and consistency.
Because it is a relatively simple process, the production of jams and jellies is not expected to change dramatically. What is apparent is that new flavors will be introduced. Certain vegetable jellies such as pepper and tomato have been marketed successfully. Other, more exotic types including garlic jelly are also appearing on grocery shelves.