Wash pears. Cut in half lengthwise, core and peel. Place completed pear halves in a bowl of water with some lemon juice in it.
Put a broad pan such as a Dutch oven with 5 to 10 cm (a few inches) of water in it on to start boiling.
Put the apple juice in a saucepan and set on a burner to start heating.
Poach the pears one layer at a time in the pot of boiling water, until they are hot throughout.
Bring apple juice to full boil.
Pack hot pears into half-litre (US pint) or litre (US quart) jars, core cavity downwards. It's okay to layer them in the jar.
Leave 2 cm (½ inch) headspace.
Tuck 1 cinnamon stick in each jar.
Top up each jar with the hot apple juice.
Debubble, adjust headspace.
Wipe jar rims.
Put lids on.
Process in a water bath or steam canner.
Process half-litre (US pint) jars for 20 minutes; litre (US quart) jars for 25 minutes. Increase time as needed for your altitude.
Best after at least a few weeks of jar time.
