I work at a liquor store. Before I worked at a liquor store I worked at a store that sold the stuff to make various liquors and alcoholic beverages. I have, over the years, been privy to many misconceptions and false beliefs about alcohol. One of the most common is the belief that the longer a wine sits in the bottle the more alcohol will be produced. This is not true and if it were true it would suggest that really really old wine, say from the 1940's, would be guaranteed to knock you on your ass. But thats not really the misconception I wanted to talk about today.
Screw caps, yes they are less romantic than a cork; but as far as sealing a bottle of wine goes that is just about their only draw back. Cork is not the best way to seal a wine and in no way does a corked bottle suggest better quality than a screw caped bottle. A lot of people seem to think that a screw cap is a sign of a cheap or inferior wine. You cannot deduce as much simply by looking at the sealing method. In fact a screw caped wine has a higher likelihood of being better than a wine that has a cork. The problem with cork is it is organic and as such it is a friendly environment for fungi. It's not often that fungi will harm the wine. Estimates range from 5-10% of wine sealed with a cork will develop cork taint due to fungus which will completely ruin the wine (if you should ever have this happen to you just bring the wine back to the store and they should replace it).
Screw caps don't mess up your wine. While the old world (Europe) is totally against the new seal hunt, the rest of the world has been searching for new seals that won't taint your wine. Mostly the seal of choice is the screw cap but there are some other types. What it all boils down to is that a screw cap does not reflect the quality of a wine. The new world tends to embrace the screw cap, with Australia and New Zealand leading the way. The old world tends to shun the screw cap. Next time you are browsing the liquor store just take a moment to check out which wines are sealed with which method and don't be afraid of the less romantic sealing method!