When fixing yourself a PB&J, there are bigger questions than just chunky or smooth peanut butter. Chief among them being: should you reach for a jar of jelly or jam? Or pass over the J entirely in favor of preserves? And what about marmalade for that matter? Or compote or conserve? Here’s everything you need to know about the jelly family tree.
For starters, most jars of shelf-stable fruit spreads – your jellies, jams and the like – are filled with a combination of three chief ingredients: fruit, sugar and pectin. Pectin – the only ingredient you might not have heard of – is a type of starch called a heteropolysaccharide that occurs naturally within the cell walls of fruits and vegetables, giving them form and structure. When heated to 220°F, exposed to a bit of acid (think lemon or other citrus juice) and left to cool, pectin reforms as a gel.
The firmer a fruit, the higher the pectin content. This is why jellies and jams made from soft fruits like strawberries, raspberries and grapes often still rely on pectin gathered from fruits like apples, pears, apricots, plums, quince or oranges. In the case of oranges in particular – and lemons, grapefruits and limes as well – the majority of the pectin content is found in the firm rind of the fruit. More on that in just a bit.
As fruit ripens on the vine, branch or bush, the pectin within is broken down by enzymes naturally present in the fruit itself. As the pectin content diminishes, the fruit softens, and eventually rots. Because of this, fruit spreads are created using under-ripened, or just barely ripened, fruit still rich with pectin.
Jellies, jams and preserves are each variants of this fruit, sugar and pectin trifecta, each with a specific formula.
Jelly is made from cooked, clarified fruit juice, sugar and pectin. After cooking, but before it has had time to cool, the mixture is strained through a fine mesh jelly bag to remove impurities and solids. Once it has cooled and solidified, you are left with a firm, transparent fruit spread. Jelly is notable for its dense gel, it’s gemstone-like clarity, and for the fact that it is made with fruit juice instead of fruit.
Jam, like jelly, contains both sugar and pectin. It differs, however, in that real, crushed fruit or fruit pulp is used instead of fruit juice. The crushed fruit is cooked down, usually with a bit of acid, until the fruit loses its shape and consistency. Then sugar and pectin are added to the mixture. Once cooled, jam takes on a translucent quality. Light still passes through it, but visible bits of fruit are suspended throughout.
Because of jam’s inclusion of real fruit instead of juice, it may seem like the healthier option of the two. But let’s call a spade a spade here. To qualify as a jam under the U.S. Food and Drug Administration (FDA) guidelines, a product must still contain more than 55% sugar. Sugar, after all, is the preserving agent in each of these mixtures, drawing out moisture from the fruit.
Preserves take things a step further than even jam, suspending fruit within the sugar-pectin-cooked fruit mixture before it has had time to chill. Though preserves are something of a catch-all term, true fruit preserves critically contain within them either whole fruits – think cherries, blueberries or currants – or uniformly cut pieces of larger fruits like apples, peaches or guava. Preserves are impossible to see through, with light being obstructed by countless tiny pieces of fruit.
Marmalade may seem similar to preserves or jam, with the tiny pieces of suspended fruit present within, but it is actually more closely related to jelly. Marmalade is made by adding tiny pieces of fruit rind – most famously, orange – to a jelly mixture made from citrus juice, sugar and pectin. Citrus rind, remember, is rich in pectin. When preserved in marmalade, it provides both a tartness and texture unlike its canned cousins.
Another fruit spread related to jam is conserves. In fact, like squares and rhombuses, all conserves are jams, but not all jams are conserves. That’s because conserves are specifically made from multiple types of fruit. That mixed berry jar of jam on the shelf of your refrigerator? It’s actually a conserve. Likewise, jars of fruit mashups like raspberry-peach or cranberry-apple are all technically conserves.
Compote and coulis
Two further types of cooked fruit spreads, albeit ones you’re unlikely to find preserved in a jar, are compote and coulis. Both are mixtures of fruit and sugar that eschew pectin in favor of a drawn-out, slow cooking method. Compote is a textured reduction containing pieces of the fruit, while coulis takes an added ride through a food processor until it is made perfectly smooth. Both compote and coulis are usually made for immediate consumption.
Finally, there’s fruit butter. That’s what you get when a processed-until-smooth coulis continues to be slowly cooked down until much of the moisture is evaporated out. The puree that remains takes on a thick, almost creamy consistency that we call fruit butter. That is, if it is made from one of just eight fruits. If your butter isn’t made from apples, pears, peaches, grapes, apricots, plums, quince or prunes, then it cannot technically be labeled fruit butter, under FDA rules.