I've got a box of peaches and I want to make jam. Most of the recipes I've looked at are pretty straightforward, but what is pectin, and why do they call for so much sugar—like five cups of sugar for four cups of peaches? WTF? My peaches are already almost too sweet.
A: Pectin is a thickener used in most jams. Unlike gelatin, which is often made from animal tissue like horse hooves, pectin is a plant-based molecule that's important in supporting cell structure and is usually derived from processed apple, orange and beet material. Pectin comes in powdered and liquid forms, which have different characteristics and behaviors.
Sugar activates the pectin and makes it do its thickening thing, so the balance of fruit, pectin and sugar determines whether you get peaches in syrup or peach jam. Messing with that balance by, say, using less sugar than a recipe calls for can take you into uncharted territory.
There is a brand of pectin, available online and in many stores, called Pomona's Universal Pectin, that uses an included calcium-based solution to activate the pectin instead of sugar, allowing for low- or zero-sugar canning.
Personally, I have no need for sugar on my peaches, nor do I need my peaches thickened. I like my peaches in a sugar-free, cider-based heavy syrup, which can be heated into a sweet sauce, spooned over yogurt or cereal, or slurped directly from the jar.
Blanch your peaches briefly in boiling water, until the skins loosen and can be easily slipped off. Cut the naked peaches into quarters or even smaller slices, and add them to a pot in which 1 quart of apple cider—I juice apples from my tree—for 10 pounds of peaches is heating. Bring the peach-cider combo to a boil, then mix in six 3-ounce packets of liquid pectin, which will mingle with the natural peach sugars, the naturally occurring pectins in the apple juice and the peach particles to make a heavy sauce. Heat the peach cider mixture, stirring often, until it comes to a boil. Immediately ladle the hot peaches and syrup into sterile jars, making sure the syrup covers the peaches, and cap with sterile rings and lids. The lids will seal as the jars cool, and the peaches will be bright, gorgeous and delicious.