Peel pears; cut into halves and core.
Treat to prevent darkening.
Rinse and drain.
Cook a few pears at a time in water until heated through.
Pack hot into hot jars, leaving 1/2-inch head space.
Place 1 cinnamon stick in each jar.
Heat apple juice just to a boil.
Pour hot over pears, leaving 1/2-inch head space.
Remove air bubbles.
Process pints 20 minutes in boiling water bath.