Until the good fairy Electricity entered the scene with her sophisticated appliances like refrigerators and freezers, jarring, picking, and preserving food was more than a locavore's hobby—it was a way of life. Buying strawberries from Mexico in the dead of winter just wasn't an option, so people looked for ways to prevent food from spoiling to stave away hunger during the cold season or long journeys by sea or land.
Smoking, salting, drying and fermenting all came along before canning technology and the use of sugar as a preservative. Although the Greeks and Romans stored fruits in honey, sugar was an expensive luxury. Jams and jellies didn't become common until the 19th century when sugar became cheap enough to use in large quantities.
Today, preserves are about more than just making it through the winter. Creating unusual flavor combinations is also part of the fun. Add a kick of heat, a touch of tartness, something boozy, herbal, or spiced, and preserves become a little more exciting. Store shelves these days offer a daunting array of small-batch products. But as you stare at the aisles of jellies, jams, conserves, and compotes, do you know what defines one type of preserves from another? It all comes down to the kind of fruit that's used, the way the product is prepared, and the proportions of different ingredients.
Let's get into the nitty-gritty.
Ingredient Roll-Call
Fruit
Fruit is the star of the show here, and the first step to making any sort of preserves is selecting your fruit! Once you've got the right mix of perfectly ripe and just-slightly under-ripe fruit, you're good to go. Avoid overripe fruit, which will contribute overcooked flavors, leathery texture, and lack some of the pectin and acidity that are essential for good preserves.
Sugar
Sugar's the backup singer, but your star can't last long on stage without her. Just like salt, sugar acts as a preservative. Sugar bonds with water, drawing moisture out of living cells, thus making the fruit inhospitable to microbes that can cause spoilage.
Since water content correlates directly to shelf life, the efficiency of the jelly as a preserving agent depends on its concentration—thicker syrup (aka: a jelly with higher sugar content), typically has less water content and is therefore less perishable.
Oh, and sugar also makes preserves deliciously sweet. Although regular table sugar is the typical go-to, other sweeteners like brown sugar, corn syrup, and honey can also be used.
Pectin
Ok, maybe we're stretching the metaphor a bit, but if fruit is the star and sugar's the backup singer, let's call pectin the Autotune of your jam or jelly concert. Pectin keeps things together: it's a naturally occurring carbohydrate with thickening and gelling properties. Unlike gelatin and agar agar, pectin requires both heat and acid in order to gel.
Commercially available pectin powder is often derived from apples, but many other fruits also contain high levels of pectin. Since different fruits have varying levels of natural pectin, the type of fruit you use (and its ripeness) will determine the amount of necessary additional pectin. For example, preserves made with apples, quinces, plums, and blackberries typically do not need additional pectin—they sing right on key without the Autotune—while fruits like apricots, blueberries, and peaches usually do need a little help.
If you're adding powdered pectin to your jam, it's best to whisk the pectin together with granulated sugar to prevent it from clumping and forming hard lumps.
Acid
Acidity interacts with the pectin—naturally occurring or added—to create a gel. This means that a bit of lemon, vinegar, or citric acid not only helps to balance your jam's flavor with a little tartness, it also helps create the characteristically spreadable texture of jellies, jams, and marmalades. The ideal pH for pectin gelation is between 2.8 and 3.5— about the acidity of orange juice.
Ok. Got it. Now what's the difference between all those preserves?
So glad you asked.
Preserves
The word preserves is often used as an umbrella for all sorts of preserved fruit spreads. Sometimes, though, people use the term to refer to preserved whole fruit or fruit cut into large uniform sized pieces. The fruit can be stored in its own juices, syrup or even water. The storage liquid is typically clear-ish and is sometimes slightly gelled using pectin. The fruit maintains its shape during cooking and should be tender and plump.
Use it: Throw these bad boys on some vanilla ice cream, waffles, or warm chocolate cake. Invite me over, too, will ya?
Jam
This is what English muffins were made for. Jam consists of fruit that's crushed or chopped and cooked with sugar (and sometimes pectin and an acid) until the pieces of fruit are soft and lose their shape. As the mixture cooks, water evaporates and it thickens to a spreadable consistency, though it still may have some pieces of fruit. Sugar acts as the primary preservative.
The FDA has a whole bunch of rules that determine which products can be legally labeled as jam. If you're starting with berries, tomatoes, oranges, or pineapples, the ratio must be 47 parts by weight fruit to 55 parts sugar. If you're starting with stone fruit, currants, guava, or gooseberries, the ration must be 45 parts fruit to 55 parts sugar. That fruit quantity refers to the weight of the fruit that's already been pitted, seeded, and skinned. Since the fruit also contributes natural sugars to the equation, the FDA requires a "soluble solids test," which essentially tests the sugar content using a handy dandy tool known as a refractometer. If you're planning on turning your jam hobby into a business, any jam you want to label 'jam' must have not less than 65% soluble solids. But, if you're makin' jam for breakfast tomorrow, just do what tastes right to you.
Use it: Try spreading blueberry lavender jam between layers of lemon cake, or think savory with a smear of tomato jam for a kick of sweet acidity on a grilled cheese sandwich. This red plum jam is excellent with beignets.
Jelly
The primary difference between jam and jelly is that jelly is strained for a gem-like clarity without fruit solids. To get that bright, crystal-clear consistency, most fruits are crushed and cooked to extract their juice. The mixture is strained through a jelly bag, which is made of a fine mesh fabric that ensures that no fruit particles slip through. If you want to DIY it, use a metal strainer with several layers of cheesecloth. Since dry fabric absorbs flavor from the juice, the jelly bag (or cheesecloth) should be moistened first with cold water, then wrung out to get rid of any excess moisture. After straining, the juice is boiled rapidly with sugar (and sometimes pectin) so that when it sets, it holds its shape. Jelly is typically firmer than jam, but not so firm that it's gummy-like. According to government regulations, jelly must contain at least 55% fruit juice.
Use it: Jellies are perfect slathered over French toast, or if you're feeling classic, make a variation of PB&J using non-traditional flavors like pomegranate jelly and cashew butter.
Conserves
Jams made from a mixture of various fruits are called conserves. Basically, all conserves are jams, but not all jams are conserves. Make sense? Conserves usually contain fruit mixed together with sugar and sometimes nuts and dried fruits.
Use it: Make biscuits or English muffins and spread them with conserves.
Compote
Compote can be made with fresh or dried fruit (whole or cut into pieces) that's slowly cooked in a sugar syrup (sometimes containing liquor and spices). Slow cooking is important for the fruit to maintain its shape.
The Culinary Institute of America considers compote to be one of two types of fruit sauce: there's coulis, made with smooth, pureed fruit and then there's compote, which is a chunky mixture. While preserves and conserves are typically jarred, compotes are often (although not always) made and used immediately as a component of a dish. Compote applications can be either sweet or savory.
Use it: Pile some compote onto a stack of pancakes, or serve it alongside duck confit or a seared duck breast... or foie gras.
Marmalade
The word marmalade was derived from the Greek melimelon, which referred to quince stored in honey. Today, marmalade is a soft jelly that contains pieces of fruit rind (usually citrus). Marmalades have both a sweet and sour flavor, and the rind of the fruit imparts a mild bitterness. Although cooked rinds become tender, they maintain their structure, giving the spread a distinct candy-like bite.
Not only do we use citrus peel for marmalade because it contains high amounts of flavorful and aromatic oils, but the peel also contains very high levels of pectin. In fact, when commercially manufactured pectin is not derived from apples, it is often made from citrus. As a result of citrus peel's naturally high pectin content, marmalades rarely require additional pectin.
Use it: Marmalade, whether it's made from lemon, tangerine, or other fruit, gives breakfast a little boost, balancing the butteriness of a scone or other pastry with tartness. Marmalade also makes a great glaze for cured meats like baked ham.
Fruit Butter
Unlike jellies, jams, and marmalades, fruit butter is not jellied. Instead, butters rely on the fruit's natural body to create thickness—the fruit pulp is cooked with sugar for a longer period of time in order to achieve a dense texture (longer cooking means more moisture evaporation!) Fruits containing less moisture to begin with (like apples and pears) lend themselves to making deeply flavored butters.
According to FDA rules, products labeled 'fruit butter' must be made from these eight fruits: apples, apricots, grapes, peaches, pears, plums, prunes, and quince.
Use it: Whether you go for classic apple butter, pumpkin butter, or something a little different, fruit butters are great on graham crackers or spooned over yogurt.