Make 3 liters of juice from the apples and pears, if you like it easier (like me sometimes) you can use the finished juice.
Bring the juice to the boil in a heavy cauldron and then reduce to about 500 to 600 g, uncovered, in about 1.5 hours. This juice turns into syrup and becomes darker and darker.
Pour the finished syrup, which is then tough, into a suitable glass.