, washed, trimmed, and chopped in 1/2
- After your fruit has been prepped as indicated above, combine the rhubarb, sugar, water, lemon juice, spent halves (with 1/8? of the blossom and stem ends removed), and seeds in a large non-reactive bowl; set aside at room temperature for 1-2 hours.
- Pour the contents of the bowl into a large, non-reactive pot; as you are spooning the fruit in the pot, set aside the lemon seeds and tie them up in a small cheesecloth bag. Add this bag to the pot and bring the ingredients to a boil over medium-high heat. Continue to cook, stirring the jam constantly, for about 15 minutes. Skim foam from the surface of the jam as necessary.
- Drop the heat to medium and hold the jam at a constant simmer, checking often to ensure the jam isn’t scorching on the bottom of the pot. After 15 minutes, check to see if the jam is set by placing a small spoonful on a plate that has been in the freezer for at least an hour; the jam is set when it holds its shape on the cool plate. If it seems too loose, continue cooking it over medium-low heat until it’s set.
- Remove the seed bag and spent lemon halves. Ladle the jam into hot, sterilized jars, leaving a 1/4? headspace. Process in a hot water bath canner for 5 minutes if using half-pint or pint jars. Store in a cool, dark, and dry place for up to one year.