Stem and wash grapes, and keep in ascorbic acid or lemon juice. Dip ripe but firm peaches, a few at a time, in boiling water for 1 to 1-1/2 minutes to loosen skins. Dip in cold water and slip off skins.
Cut in half, remove pits, cut into 1/2-inch cubes and keep in solution with grapes. Peel, halve, and core pears. Cut into 1/2-inch cubes, and keep in solution with grapes and peaches.
Combine sugar and water in a saucepan and bring to boil.
Drain mixed fruit. Add 1/2 cup of hot syrup to each hot jar. Then add a few cherries and gently fill the jar with mixed fruit and more hot syrup, leaving 1/2-inch headspace.
Remove air bubbles and adjust headspace if needed. Wipe rims of jars with a dampened clean paper towel. Adjust hot lids and process in a water bath for 20 minutes.