Are Screw Caps Really Bad?

Many people think that wines sealed with screw caps are cheap and cannot be aged. Is this statement correct?
1. Cork VS. Screw Cap
The cork is made from the bark of the cork oak. Cork oak is a type of oak grown mainly in Portugal, Spain and North Africa. Cork is a limited resource, but it is efficient to use, flexible and strong, has a good seal, and allows a small amount of oxygen to enter the bottle, helping the wine to continue to develop in the bottle. However, some wines sealed with corks are prone to produce trichloroanisole (TCA), causing cork contamination. Although cork contamination is not harmful to the human body, the aroma and flavor of the wine will disappear, replaced by the musty smell of the wet carton, which will affect the taste.
Some wine producers started using screw caps in the 1950s. The screw cap is made of aluminium alloy and the gasket inside is made of polyethylene or tin. The material of the liner determines whether the wine is completely anaerobic or still allows some oxygen to enter. Regardless of the material, however, screw capped wines are more stable than corked wines because there is no cork contamination problem. The screw cap has a higher degree of sealing than the cork, so it is easy to produce a reduction reaction, resulting in the smell of rotten eggs. This is also the case with cork-sealed wines.
2. Are screw capped wines cheap and of poor quality?
Screw caps are widely used in Australia and New Zealand, but to a lesser extent in the United States and Old World countries. Only 30% of wines in the United States are sealed with screw caps, and it is true that some of the wines here are not very good. Yet up to 90% of New Zealand’s wines are screw capped, including cheap table wines, but also some of New Zealand’s best wines. Therefore, it cannot be said that wines with screw caps are cheap and of poor quality.
3. Can wines sealed with screw caps not be aged?
The biggest doubt people have is whether wines sealed with screw caps can age. Hogue Cellars in Washington, USA, conducted an experiment to compare the effects of natural corks, artificial corks and screw caps on wine quality. The results showed that screw caps maintained the fruity aromas and flavors of red and white wines well. Both artificial and natural cork can cause problems with oxidation and cork contamination. After the results of the experiment came out, all the wines produced by Hogg Winery were switched to screw caps. The reason why the cork closure is good for wine aging is that it allows a certain amount of oxygen to enter the bottle. Today, with the advancement of technology, screw caps can also control the amount of oxygen entering more precisely according to the material of the gasket. It can be seen that the statement that wines sealed with screw caps cannot be aged is not valid.
Of course, listening to the moment when the cork is opened is a very romantic and elegant thing. It is also because some consumers have a feeling of oak stopper, many wineries dare not use screw caps easily even if they know the benefits of screw caps. However, if one day screw caps are no longer considered a symbol of poor quality wines, more wineries will use screw caps, and it may become a romantic and elegant thing to unscrew the screw cap at that time!