J: Jams, Jellies (and Preserves and Conserves)

A jar of berry jam with a spoon dipping into it.


Photograph from iStockphoto.com


What's the difference between jelly and jam? Can you make a peanut butter and jam sandwich? Technically that's still PB&J, right? And what are preserves? Marmalades? And conserves? These days, when it's easy to just pick up a jar of Smucker's at the supermarket, why should we bother to try to make sense of these terms? Well, because April 2nd is National Peanut Butter and Jelly Day! And because homemade jams and jellies are easy to make and delicious to eat.

In the days before refrigeration, an entire growing season's worth of fruits and vegetables were preserved for use throughout the winter. Cucumbers transformed to pickles, and tomatoes and beans were canned and "put up" in the pantry or root cellar for the winter. Fruits were mixed with sugar to create jams, and to give a taste of summer to a bitterly cold February morning's breakfast. The history of jam dates back to the Greeks, who used honey to preserve quinces. In the 16th century, cane sugar came to Europe from the new world, and it was used to preserve fruit, hence the term preserves.

All of these concoctions that we know today as jams, jellies, marmalades, and conserves are a mixture of fruit and sugar. The basic preparation involves crushing ripe fruit to release its juice, then adding sugar and heating the mixture to a boil, cooking it until it's ready to set, and then placing the resulting syrupy mixture in jars for storage. What differentiates all these preserves? Jellies are made only from the juice of fruits; the solids are strained from the juice before the sugar is added. With jams, the fruit chunks are left in the mixture. Marmalades are jellies in which pieces of fruit are suspended, not crushed. And conserves are a mixture of fruits, often citrus, with nuts and raisins added. Of course, these are the American labels. In the UK, jelly can refer to what Americans know as Jell-O. And Americans tend to call jams "jelly" anyway, like in their peanut butter and jelly sandwiches. So I'm not sure things are any clearer now.

Growing up, I was put off the idea of making jam from scratch because I thought it was hard. Both of my grandmothers make homemade jam and jelly, and I'd always hear stories about jams not setting. But a simple understanding of the role of pectin (a polysaccharide found in the cell walls of plants) in your preserving process can help prevent setting snafus. When fruit and sugar are heated to 221°F (105°C), the acid and pectin in the fruit react with the sugar. Two important things happen: Cooking with such a concentration of sugar kills off most microbes, and, as the mixture cools, the pectin helps the jam to "set", or solidify. The result is a spreadable mixture that won't spoil.

It's important to understand that while all fruit has pectin, the level and quality of pectin varies not only among fruits (apples have a lot, strawberries very little), but even within fruits. The tougher parts of a plant have more pectin than the softer parts. And as a fruit ripens, the pectin breaks down, so depending upon an apple's ripeness, its level of pectin varies. All of this is a long way of saying that if you rely on the naturally occurring pectin in your fruit to set your jam, you've got an unpredictable situation. And, in my experience, unpredictability leads to hard times in the kitchen.

Of course, for hundreds of years, jam makers have known about the pectin predictability problem. They've solved it by adding extra pectin. Initially this was done in the form of adding apple juice or jelly to a batch of preserves. In the 20th century, the advent of pectin powders and syrups (such as Sure-Jell and Certo) made it easy for the home cook to create perfectly set batches of jams and jellies.

I'll admit that the one time I made jam without additional pectin (a lovely recipe for Strawberry with Raspberry Juice and Balsamic Vinegar), it failed to set and I ended up with a lovely magenta syrup for ice cream. Making jam in this fashion takes more practice and experience, because you need to be familiar with what a setting, boiling cauldron of sugary berries looks like. And you can "check the set," as they say, by putting a drop of your mixture on a cold plate and examining its consistency. If it's loose and runny, you need to continue cooking it.

I am now a confident home jam maker, and, while I like the authenticity of the natural pectin approach, I have to admit that the ability to ensure a good set is enough to get me to use Sure-Jell. The recipe on the pectin package will guide even a novice jammer through the process. All you need to do is collect two quarts of ripe fruit and your result will be the best-tasting jam or jelly you've ever had. Perfect for spreading on your morning toast or making yourself a tasty peanut butter and jelly sandwich.

Strawberry with Raspberry Juice and Balsamic Vinegar
From Mes Confitures: The Jams and Jellies of Christine Ferber, by Christine Ferber.

Ingredients 1 3/4 pounds wild Mara strawberries, or 1 1/2 pounds net*

4 1/4 cups granulated sugar

Juice of 1 small lemon

1 1/4 pound raspberries

1 2/3 tablespoons balsamic vinegar

5 peppercorns, freshly ground

1. Select small strawberries. Rinse them in cold water, dry them in a towel, stem them, and halve them. In a bowl, combine the strawberries, sugar, and lemon juice. Cover with a sheet of parchment paper, and let them macerate, refrigerated, overnight.

2. Next day, place the raspberries into a saucepan with 3 1/2 ounces water, bring to a boil, and boil for a few minutes. Strain this mixture through a chinoise, pressing the fruit lightly with the back of a skimmer. Set the collected raspberry juice aside.

3. Pour the macerated strawberries into a sieve. Bring the strawberry syrup to a boil in a preserving pan with the raspberry juice. Skim and continue cooking over high heat. The syrup will be sufficiently concentrated at 221°F on a candy thermometer.

4. Add the macerated fruit, pepper, and balsamic vinegar, and bring to a boil once more. Skim, return to a boil, boiling for about 5 minutes while stirring gently. Check the set. The strawberries should be translucent, like preserves.** Put the jam into the jars immediately and seal.

Where Mara strawberries are not available, use local, wild strawberries combined with ripe, locally grown, domesticated strawberries.

** Note from Meg Hourihan: Argh! Didn't I just say preserves are the same as jam? Why's she confusing things here? The world of jams and jellies is messed up, ladies and gentlemen. No doubt about it.