Differences in Consistency and Texture
The first difference most people notice has to do with overall appearance. Jams tend to look somewhat chunky even in the jar, and it is often possible to see pieces of fruit or tiny seeds in the spread. Most of the time, this is desirable; the main idea behind jams is to preserve the fresh flavor of a fruit, berry, or vegetable, and the best way to do this is often to include whole slices or segments.
Jellies almost never contain chunks and tend to have a very even, uniform consistency. They taste like fruit, but rarely ever contain it. Jelly will usually spread very evenly, and often has a translucent appearance. Some people describe it as a sort of sweetened, solidified juice.
The difference between jam and jelly appearance usually traces pretty directly to differences in ingredients. Jam makers usually begin by mixing fruits, berries, or other produce with sugar, and then they heat everything up until the mixture forms a thick syrup. Jellies, on the other hand, almost always begin with juice. Cooks simmer fruit or other extracts with sugar and a number of jelling agents until the mixture “sets up” or solidifies.
Juices and whole fruits are usually related, but lead to very different outcomes where preserves are concerned. A jam made from strawberries, for example, may taste similar to a jelly made from strawberry juice, but the jam will usually contain actual pieces of the berry whereas the jelly will not. The jam will also usually have a bit more tartness thanks to the fruit’s presence.
Another difference between jam and jelly has to do with how, exactly, cooks get things to set up. Most fruits contain a lot of natural pectin, which is a cell tissue that acts as a thickening agent. Pectin is what gives jams and jellies their gelled consistency, but how it gets into the mix is where things diverge. Fruits typically release pectin when heated, which means than jams often don’t need much, if any, added. Juices, on the other hand, rarely contain any natural thickeners. Making jelly almost always requires the addition of commercially processed pectin.
Sugar content also usually varies between the two. Jams need some sugar to help the pectin release, but not nearly as much as most jellies. In part this is because whole fruits contain a lot of natural sugars that juices simply don’t have.
Jams and jellies are interchangeable in many recipes, and both are very popular as a spread for sandwiches and bread. Still, there are times when one is a better choice than the other. Bakers often choose fruit jams rather than jellies to use between layers of cake or as an ingredient in cookies, for instance. Its chunky texture often adds a lot of interest, and jelly used in these ways might simply absorb into the other ingredients. Jelly is often preferred as a filling for things like pastries, though, and things like jelly-filled croissants and donuts are popular in many places. Its uniform texture also makes jelly a key ingredient in many meat glazes, salad dressings, and other sauces. Jelly made from the juice of mint leaves is commonly paired with lamb, for example, and fruit jellies can be used to add subtle flavor to a variety of different dishes.
Calculating the specific nutritional information for jams and jellies is nearly impossible without knowing what each contains; a lot changes based on the type of fruit at issue, as well as how much sugar has been added in. In general, though, jams tend to have more helpful vitamins and minerals than jellies for no other reason than that they actually contain actual pieces of produce. Whole foods are almost always more nutritious than juices.
Consumers must usually also watch out for additives and preservatives. Many of the jams and jellies made for the commercial marketplace contain a lot of artificial ingredients and preservatives. Some improve the natural jelling process, while others help lengthen shelf life or brighten color. These sorts of additions tend to alter overall healthfulness, usually for the worse.
Other Types of Preserves
Jams and jellies tend to be quite different when it comes to how where they fit on the spectrum of other fruit preserves, too. Marmalades are jam-like reductions of primarily citrus fruits, for instance, and chutneys are often described as jams that are filled with a balance of sweet and savory ingredients, usually including a number of spices. Fruit butters usually fall somewhere in the middle; these preserves usually include mashed fruit that has been blended to an even consistency that is more jelly-like. The key ingredients are often quite similar across the board, but how those ingredients are processed and handled is usually where the major differences lie.