Does red wine take longer to age under screw cap or cork? The jury is out

As a long-term wine-drinker, I find that red wines under screw caps need 20 years of ageing, whereas 10 years is the norm for cork. Do screw caps slow the ageing process?

—R.C., Red Hill, VIC

Only young people would disagree that things that age slowly are better in the long run. You describe yourself as a “long-term” drinker of wine, so I’m sure you’re not a callow youth. And if you’ve got more years behind you than ahead, it’s perfectly understandable that you don’t want your wines to age too slowly. Some senior wine-lovers joke that they don’t even buy green bananas!

My views on this subject are in two parts. The first is that the average rate of maturation of screw-capped red wines is slower than the average under a cork
closure simply because a screw cap is equivalent to the best cork at keeping air out.

Cork is a more permeable substance and all wine corks are different, letting in varying amounts of air. The worst corks admit so much air that the wine is prematurely oxidised and spoilt. The best, on the other hand, make a near-perfect seal. However, I’m not convinced wine under a cork closure ages twice as quickly as the same wine under a screw cap.

The second observation is that the “cells” inside a piece of cork contain air, and some of that trapped air is slowly released into the wine as it ages. Some experts also believe that there are other chemical interactions between cork and wine that impart additional, desirable organoleptic effects (that is, changes that are perceived by our sense organs), but this is still a little-understood area that needs more research.

While the jury is still out on this topic – and it is, I’m afraid – everyone has an opinion. As you said in your letter, every winemaker you talk to is likely to have a different view.

One thing can be guaranteed: those who use screw caps will likely tell you cork is rubbish, while those who’ve stuck with cork will tell you it’s the best.

Got a drinks question for Huon Hooke? thefullbottle@goodweekend.com.au