Wash crabapples and remove stem and blossom.
Juice using your preferred method:Mechanical juicerRun crabapples through the juicer and skim of foam and sediment.Steam juicerCut crabapples in half and process in a steam juicer for 30-60 minutes, or until juice is released.Boiling waterCut crabapples in half and then cover with 5 cups of boiling water. Let sit for 24 hours, then strain juice and discard solids. Fill mason jars to ¼ inch headspace, wipe jar rims with a paper towel wetted with white vinegar, and attach two part lids to fingertip tightness.
Process in a boiling water canner for 10 minutes, or if at elevations of 3,001 to 6,000 feet process for 15 minutes.
Remove canner from heat and let sit for 5 minutes. Carefully remove jars from canning pot and set on a thick towel on a counter or table overnight. In the morning, check that jars have sealed; sealed jars can be stored at room temperature for up to 18 months, and unsealed jars should be refrigerated and consumed promptly.