Before you can press apples into juice, they must be crushed into a finely divided fruit mass.
Crushing is important to get the highest possible juice yield. It is also important that the fruit mass has the right consistency, not too fine or too coarse.
It is not enough to slice the apples with a knife, as the pieces will be too large, provide too much resistance, and it will not be possible to press fruit juice out of them.
To crush apples or pears properly, you need a special fruit crusher.
There are both hand-operated and electric fruit mills and crushers, which cover all levels of juice production. These machines give the fruit mass the consistency that is suitable for juicing.