What You Need to Know About Pectin

Summer might be over, but that doesn't mean we can't still jam. As we welcome fall with open arms and a closet full of chunky sweaters, we also get to usher in the opportunity to smear apple jelly on everything in sight — and get inspired by new recipes in our favorite canning books.

As you gather your canning equipment, and peel and chop late summer and fall fruit with an eye to preserving it, you may wonder when and how you should use pectin when making homemade jams and jellies. Here's what you need to know.

What is pectin?

"[Pectin] is what gives a jam its thickness, and a jelly or marmalade its jelly-like consistency," explains Jessica Koslow, author of The Sqirl Jam Book. All fruit naturally contains pectin; it's found in the peel, seeds, and cores. For home cooks, pectin is most often used when making jams and jellies. Some jam recipes call for commercial pectin to be added to the mix. Here's when you should and shouldn't use pectin, the suitable substitutes for this thickening agent, and how to make pectin at home using just two ingredients: apples and water.

Why cooks use pectin

When we talk in recipes about added pectin, we're referring to commercial pectin sold in a dried or liquid form. It's added to homemade (and commercially produced) jams and jellies to not only thicken the cooked fruit into a spreadable form, but also to create a higher yield. "Commercial pectin is going to set reliably every time and requires a lot less guesswork to tell if jam is ready," says Camilla Wynne, author of Jam Bake.

When you make jam, you start by cooking down a batch of fruit — say strawberries or peaches — with sugar and a little bit of lemon juice. By cooking the fruit, you're slowly releasing the water content to thicken the mixture. But as the water evaporates, the yield of the mixture in the pot decreases. By adding pectin near the beginning of the cooking process, the fruit mixture will thicken to the ideal consistently nearly immediately, allowing you to fill many more jars of jam than you would without pectin.

First, know your fruit

Fruits have varying degrees of pectin levels, and that will impact your jam process. "While you can generally feel comfortable omitting any added pectin from recipes that call for high-pectin fruits, the same can't be said for recipes that use low-pectin fruits," Wynne notes. Low-pectin fruits include tropical and peak summer fruit such as cherries, strawberries, pears, peaches, and rhubarb. Other berries like blueberries, raspberries, and blackberries are somewhere in the middle. The good news is that fall is a great time for high pectin fruit, says Wynne; crabapples, apples, quince, cranberries, and plums all have extremely high levels of pectin, which means that adding commercial pectin to jellies and jams made with these fruits isn't so essential.

When to use dried or liquid pectin

Most recipes will call for a specific type of pectin, but if they don't, Wynne advises home cooks to default to the standard powdered version. Koslow adds that the two forms are used entirely differently during the cooking process. "Powdered pectin traditionally should be added to the fruit pre-boiling, while liquid pectin must be added to the hot liquid mixture near the end of boiling," she says, adding, "Liquid pectin also has a shorter shelf life." But they're not entirely different — both dried and liquid pectin are made from citrus peels, which is the highest pectin-yielding fruit and requires less sugar to set.

The downsides of cooking with pectin

There are, however, a couple of reasons to not use pectin when making jam and jelly. "My prejudice against pectin is that it's usually added right when the mix comes to a boil, which means that much of the water hasn't cooked off so the delicious fruit flavor isn't as concentrated. When I do use it, I add it right at the end of the cooking process just for a little bit of added security," explains Wynne.

But what if you really don't want to add pectin to your fruit spreads? You don't have to, but proceed carefully. "If you are really anti-pectin, you can omit it, but you'll need to cook the jam longer. Doing so will remove most of the water content in order to get it to set up properly and in turn, will result in a smaller yield," adds Wynne.

How to substitute for pectin

Don't have pectin on hand? One ingredient that can come to the rescue is agar agar, which is a plant-based gelatin substitute that's a suitable substitute for pectin when making jams and jellies. For tips on how to use it, we turned to Sarah Owens, author of Toast and Jam: Modern Recipes for Rustic Baked Goods and Sweet and Savory Spreads. She advises dissolving a few grams (less than a teaspoon) in a ladle or two of warm liquid from your jam or jelly, stirring it in toward the end of cooking. Bring your preserves to a boil for two to three minutes before transferring to sterilized jars.

Koslow's go-to substitute for pectin is a cooking method called "plumping." Plumping involves letting the fruit sit in the sugar and lemon juice for hours (or days, if you'd like!) before cooking," says Koslow. "It pulls out a lot of the moisture and allows the fruit to absorb as much sugar as possible, so when the mixture is turned into a preserve, the texture is denser than if cooked immediately after combining the fruit, sugar, and acid."

How to make your own pectin with apples

This is, hands down, the ultimate fall cooking project. You can skip the commercial stuff altogether and make your own pectin using a high-pectin fruit like apples to make a stock that can be used instead of commercial pectin. If you can, use crabapples, which have lots of natural pectin and are less sweet than other varieties. To make homemade fruit pectin, Owens says to start with four cups of water for each pound of apples. Coarsely chop the apples, including the cores. Place the fruit in a large saucepan, plus two cups of the water, and bring to a boil over medium-high heat for 15 minutes. Strain the mixture into a large bowl through cheesecloth (don't squeeze the pulp). Return the pulp to the pot and add the remaining water. Place over medium heat and return to a simmer, then lower the heat to a gentle simmer for an additional 15 minutes. Turn off the heat and allow the mixture to cool for at least 10 minutes, then strain the batch once more. If you follow this recipe exactly, you should end up with appropriately one quart of apple stock, which is ready to use immediately, says Owens (it will last for up to one week in the refrigerator). Keep in mind that four cups of apple pectin stock will replace approximately three ounces of commercial liquid pectin.