Glass bottle filling lines can rinse, fill, cap, and label water, soft drinks, beer, and other beverages in glass bottles. Since glass bottles are rigid but fragile, the filling line has heavy-duty conveyors with low-impact bottle transfer to reduce breakage. Before filling, the bottles pass through a vacuum stage that removes the air inside them; sterile gas then replaces the extracted air, leaving less oxygen in the bottles and reducing the risk of oxidation. Electronic counter-pressure (isobaric) filling keeps the pressure balanced as the beverage is filled in the bottles, reducing foaming and helping protect the beverage from oxidation.