Winemaker Notes: Screw Caps Versus Corks

This week, we will discuss the relative merits of screw caps versus corks.

Exploring the relative merits and pitfalls of each is a very difficult discussion.

Primary is consumer acceptance and expectation, which also often includes a little misinformation and pre-conceived ideas on what corks can and can’t do, and what screw caps can offer.


Corks have a long-standing history, and generally will be well-received by most customers. In fact, consumers have been polled, and it has been found that most consumers believe better wine is always corked, not screw-capped. Why is this true? Well, corks are traditional. If you go to a discerning establishment, they often hand you the cork—and many people have no idea what they are supposed to do with it - look at it, and judge it somehow ‘okay’….

In truth, the factor they are supposed to be looking for isn’t something they can visually test; to achieve some measure of validity, you must SNIFF the cork and see if you can detect some mousy, harsh moldy notes. You must also sniff and taste the wine for evidence of cork taint, which is the issue you are being called upon to judge.

What’s funny is that not all people can even smell or detect low levels of cork taint, which is caused by levels of TCA in the wine (TCA is short for tricholoroanisole, a chemical produced by the reaction of wine with cork that has some mold factors in it). How many corks and bottles of wine will be affected? Some say as many as 5%; others argue one bottle in 100. At any rate, just because one bottle in a vintage has the cork taint does not mean they all will. But again, not all people detect the presence of TCA at low levels, and some can’t smell it at all!

What else do corks do? Well, the main thing they do is give the consumer an ‘experience’ that they like. Many people like the ritual of removing the capsule, taking out the cork, and pouring the wine.

Corks also allow a very small of oxygen in over time, which is said to age the wine gradually, through a series of chemical reactions.

Screw Caps

So why would a winery choose screw caps over corks? Initially, North America was slow to adopt the screw cap, whilst Australia and New Zealand embraced it wholeheartedly. It is now the norm down under. More and more, wineries are opting to use screw caps, some for avoiding cork taint altogether, and some for the cost/environmental concerns (cork uses tree bark). Is it really necessary to the ritual of opening a wine bottle that cork be king?

What is Our Choice?

Bee & Thistle Winery has decided to invest in Stelvin® Screw Caps and are purchasing a screw capper machine. We firmly believe them to be the best choice, and is a more environmentally conscious decision as well. Most fruit wines are not prone to needing any in-bottle aging for any length of time; if we decide to age some of our wines, we may then look at corks, but studies have shown that even high end wines are not shown to be improved, and sensory analysts could not detect a difference in cork-aged versus screw-cap aged, even after 5 and 10 years. We’ll continue to follow these types of studies.