When the new wine would ferment and expand, it would break the old skins because they could no longer stretch out. Jesus' audience would have understood the information about the wine's fermenting and expanding. (See: [[rc://en/ta/man/translate/figs-explicit]])
This can be stated in active form. Alternate translation: "the wine would spill out of the bags" (See: [[rc://en/ta/man/translate/figs-activepassive]])