The most typical techniques for crushing grapes in order to extract their juice are as follows:
1) destemming and squashing: the grapes are very first destemmed (i.e. the stems are removed) and after that squashed;
2) whole-cluster pressing: the grapes, with stems still attached, are put into a press and gently crushed in order to extract the juice;
3) foot-stomping: the grapes are put into a container, such as a vat or tub, and squashed with bare feet;
4) device squashing: the grapes are placed into a squashing maker, which utilizes steel or nylon rollers to crush the grapes. https://scarabnet.org/?p=427