In a kettle, combine water and half the lemon juice. Peel, core and quarter the pears, placing them in lemon juice mixture to retard browning until all have been peeled.
Drain liquid in kettle. Add grape juice and remaining lemon juice; bring to a boil. Reduce heat to medium; cook until pears are soft,about 20 minutes, stirring occasionally. Cool.
Press through a sieve or food mill, or process in a blender until smooth. Return puree to kettle. Add spices;cook and stir until very thick; 20-35 minutes. Remove from heat; stir in sweetener. Adjust sweetener to taste.
Pour into jars or plastic containers. Refrigerate up to 3 weeks. ( For longer storage time pour hot into hot jars, leaving 1/4 inches headspace. Process in a boiling water bath for 10 minutes. Use within 3 weeks of opening).