Neither does anyone pour freshly-squeezed grape juice into old skin bags to store it. If anyone did that, those skin bags would tear because they would not stretch when the grape juice ferments and expands. They would be ruined, and the wine would be spilled {spill} on the ground. Instead, people put new wine into new skin bags, and the bags will stretch when the wine ferments. As a result, both the wine and the bags are preserved.”