2 lbs. rhubarb stalks
2-1/2 cups granulated sugar
2 cinnamon sticks
1 Tbsp lemon juice
Wash, peel and cut the rhubarb into 1-inch pieces. Place in a bowl and add the sugar and cinnamon sticks. Set aside at room temperature 2 hours. Stir occasionally as the sugar dissolves and liquefies. Then cover and refrigerate overnight. Stir occasionally.
Drain the rhubarb and pour the juice into a large saucepan. Scrape any undissolved sugar into the pan. Place over medium heat and stir to dissolve the sugar. Then bring to a boil. Add the rhubarb and cinnamon sticks. Bring back to a boil, reduce the heat and cook at a low boil about 20 minutes, stirring often. Stir in the lemon juice. Test by putting a teaspoon of jam on a cold plate. If it does not set up within 2 minutes, cook a few minutes longer.
Remove the cinnamon sticks. Ladle the jam into clean, hot canning jars, adjust lids and seal in a boiling water bath 5 minutes. Cool on a rack.
Makes about 2-2/3 cups.