Q. What is the difference between a good bottle of wine with a screw top or a good bottle of wine with a cork? Does the fact that it has a screw top have anything to do with the quality of the wine? (this is a white wine only question).
A. Traditionally, wine was always closed using a cork since at the time that was the only air-tight means of sealing a bottle which could then be transported. Today, it is possible to seal wine using a screw-cap, but research is being done as to whether the cork adds anything to the aging process of a fine wine. Before the research can be conclusive, it is safe to say that most good bottles of wine will have corks. A few companies are just starting to experiment, so you may see more fine bottles of wine with screw caps in the future, especially given the world-wide shortage of cork.