To make sand plum juice place plums in a large pot and cover with water. Heat to boiling on medium heat until skins pop. Strain juice from the plums.

Combine plum juice and sugar in a large pot. Heat to boiling over medium-high heat, stirring occasionally, making sure it does not boil over the pot.

Turn down to low heat and simmer for 30 minutes or until it thickens. Pour into sterile jars and water bath according to the size of jars used.