*Calcium water: put 1/2 tsp white calcium powder and 1/2 cup water in a small, clear jar with lid. Shake well.
Wash and rinse jars. Let stand in hot water.
Bring lids to boil, turn off heat, let stand in hot water. Wash screw bands, set aside.
Prepare fruit by removing (if needed) and mashing.
Measure fruit into pan, add *calcium water, stir well.
Measure sugar into separate bowl. Stir pectin powder into sugar and mix well.
Bring fruit to a full boil.
Add sugar/pectin, stirring well to dissolve while mixture returns to full boil. Remove from heat.
Fill jars to 1/4" of top. Wipe rims clean. Screw on 2-piece lids.
Put filled jars in boiling water to cover.
Boil for 10 minutes. Remove from water.
Let jars cool.
Check seals: lids should be sucked down (you'll hear the pop sound).
Store for up to 1 year (stored in cool pantry).
Lasts 3 weeks once opened (keep in refrigerator once opened).