Apple-Blackberry Jelly
- 2½ medium Rhode Island Greening apples (about ¾ pound), washed and thinly sliced but not peeled or cored
- 1 cup water
- 10 cups (2½ quarts) firm-ripe wild blackberries, washed and drained
- 3 cups sugar (about)
Instructions:
The apples provide the pectin and produce a jelly of exquisite delicacy.
- Place the apples along with their stems, cores, and seeds in a medium-size, heavy nonreactive kettle. Add the water and bring to a boil over moderately high heat. Adjust the heat so the mixture bubbles gently, cover, and cook for 15 minutes.
- Add the blackberries and crush well with a potato masher; cover and boil 5 minutes more.
- Suspend two damp jelly bags over two large heatproof bowls (or line each of two large footed colanders with four thicknesses of cheesecloth and stand in the bowls). Pour half the berry mixture into each jelly bag and let the juice drip through undisturbed. The juice extraction may take an hour or longer, so have patience. If you try to rush things by squeezing the bags, your jelly will be cloudy.
- Meanwhile, wash and rinse 4 half-pint preserving jars and their closures and submerge in a large kettle of boiling water.
- Measure the extracted juice carefully; you should have 4 cups. Pour the juice back into the kettle, now rinsed and dried, and for every cup of juice, add ¾ cup of sugar. Insert a candy thermometer.
- Set over moderately low heat and bring to a boil, stirring until the sugar dissolves. Adjust the heat so the mixture bubbles gently, then cook uncovered, stirring occasionally, for about 15 minutes or until the mixture reaches the jelling point (218° to 220° F.).
- When the jelly is done, skim off the froth, then ladle the boiling jelly into the hot jars, filling each to within ¼ inch of the top. Tip: To avoid spills, use a wide-mouth canning funnel. Wipe the jar rims with a damp cloth and screw on the closures.
- Process the jars for 5 minutes in a boiling water bath (212° F.). Lift from the water bath; complete the seals, if necessary, by tightening the lids, then cool to room temperature.
- Date and label each jar of jelly, then store on a cool, dark shelf for about a month before serving.