Little spillage occurs, and if the operator is careful, the outside surfaces of the bottles remain clean and dry. Although these little machines are simple in design, they are surprisingly fast. Most gravity bottle fillers can fill two bottles per minute for each spout. For example, a machine with four spouts can fill more than eight bottles a minute, and one person is kept quite busy changing the bottles. Most wand type bottle fillers leave too much air space in the bottle.
Some winemakers prefer to fill and cork one bottle at a time.
Other winemakers prefer to fill several bottles and then cork the lot. In any event, leaving full bottles of wine open for long periods is not a good practice. Corking Standard wine corks are sold in large, sealed polyethylene bags containing one-thousand corks. The corks are sterilized with sulfur dioxide gas when packaged, and the corks remain in a sterile condition until the bag is opened. The water content of the corks is carefully adjusted just before packaging, and the humidity in the bags is carefully controlled.