Hilchos Shemittah v’Yoveil 4:23

One should act as follows: shemittah figs may not be left to dry where they are normally left to dry, but they may be left to dry in a ruin. One may not tread grapes in a vat as per usual, but he may do so in a kneading trough. Olives may not be crushed in the usual kind of press, but they may be squeezed and put into a very small press. One may grind olives in a press and then put them into a small press. The same is true in all related matters, i.e., one must deviate from standard operating procedures in whatever way he can.

Hilchos Shemittah v’Yoveil 4:24

There is a Torah obligation to divest from whatever the land produces during shemittah. Exodus 23:11 teaches: “In the seventh year, you shall let it rest and lie fallow.” Whoever locks his vineyard or fences off his field during shemittah fails to fulfill this obligation; this is also true of one who brings all his produce into his house. Rather, he must leave it all ownerless so that everyone has equal claim to it, as the aforementioned verse continues: “so the poor of your nation may eat.” He may bring a small amount into his house, just like one brings in from ownerless property, such as five jugs of oil or fifteen jugs of wine. If he brings in more than that, the produce remains permitted.