We went plum-picking in the neighborhood (any branches hanging in the street are fair game!) so I decided to make plum jam. But I also had a few ripe apricots and a peach on hand, so... stone fruit jam it is!
jars and lids
Pectin is what makes your jam set, so it's pretty vital. This recipe uses lemon pith (the white part), which I liked because it's natural and I usually have some on hand.
Sterilizing jars: Wash jars and lids well. Place in a sink filled with cold water and 4 Tbsps bleach. Soak ten minutes, then air dry on a clean rack.
Making the jam
Cut a circular sliced around each fruit, then place them in a large, heavy saucapen with high sides. Cook on med-high, stirring often, until the liquid cooks out of the fruit.
Let cool a few minutes, then pour the fruit into a large colander sitting in a larger bowl. Using a wooden spoon, stirring in a circular motion, work the fruit throught he colander - leaving just the peels, pits and fibers behind.
Pour the fruit pulp back into the saucepan.
Making the jam: Dump all ingredients in a large, thick-bottomed pot (each too much jam and you'll become thick-bottomed!). Over medium-high heat, stir the mixture until it begins to boil. As it cooks, more liquid will come out, so don't worry if it doesn't look like jam yet. Boil gently, stirring and scraping the bottom well.
To test the jam to see if it's ready, take a teaspoon of the jam from the pot and put it on a saucer. Blow on it for a few seconds and if it began to gel on the saucer, it's ready!
When the jam is ready to pour into the jar, remove the jar from the water with tongs, allowing the hot water to drain back into the pot. Fill the jar with jam, leaving 1/2-inch headspace. Wipe the rim with a clean towel. Twist the lid on, then turn the jar upside-down for five minutes to sterilize the lid. Flip the jars back over to cool completely. Once cooled, the lid should be tight and flat, which means it is properly sealed.
Store in refrigerator.