For the cherry compote, wash and pit sour cherries, reserving the juice. Layer cherries in hot rinsed preserving jars.
Add nectar to 200 ml of the collected cherry juice. Bring to a boil with red wine, sugar and cinnamon, season with Amaretto and add preserving aid if necessary.
Pour the hot liquid over the cherries so that they are covered. Wipe the rims of the jars dry if necessary. Close jars tightly with preserving rings, lids and clamps and cook (at 85°C for 40 minutes).
Remove jars, let cool, remove clamps and check lids. Store sealed jars in a dark and cool place, use open jars quickly.