Wash nectarines, halve, remove pits, and slice if desired. Nectarines are not dipped in hot water or peeled like peaches. Hold prepared fruit in ascorbic acid solution to prevent darkening.
For hot pack, place drained fruit in syrup, water, or juice and bring to a boil. Fill jars with hot fruit and cooking liquid, leaving 1/2-inch headspace. Hot pack gives better quality.
For raw pack, fill jars with raw fruit cut side down and add hot water, juice, or syrup, leaving 1/2-inch headspace.
Boiling-water process hot-pack pints 20/25/30/35 minutes and quarts 25/30/35/40 minutes at 0–1,000/1,001–3,000/3,001–6,000/above 6,000 ft. Raw-pack pints process 25/30/35/40 and quarts 30/35/40/45 minutes.