Bottle Sealants - Cork vs Screw Caps
As you may have noticed all of our Le Club wines are sealed with corks, all of varying different styles. Yet when you purchase an Australian bottle of wine almost always they are screw caps. What is the difference and is one better than the other?
Around since the beginning of the 1400s, modern Europe found it the perfect solution for containing wine within a glass bottle over time. Deemed the traditional method of sealing a bottle of wine it is hard to argue that there is anything that can match it.
Made from the Cork Oak Tree, ‘Quercus suber’, it is a renewable source of material in which the corkmakers peel off the outer layers of bark and shape into the desired corks. By not cutting down the trees completely it is a highly renewable option, allowing them to be harvested every decade. This allows thousands of bottles to be sealed with corks from a single tree over its lifespan.
“Each year, cork oak forests account for 10 million tons of CO2 absorption.” - Rainforest Alliance
The bark used is extremely malleable, ensuring the wine is drinkable at all stages without compromising the overall quality. Proven to have long term aging qualities, allowing small amounts of oxygen to seep into the wine over time to allow it to breathe and develop into a unique drink.
Unfortunately, the cork is not a perfect option for some, with its high costs and potential for TCA, not all winemakers choose this sealant. Corks can be up to 3 times more expensive than screw caps, preventing new winemakers in the business from utilising them due to the lack of money. But with time and experience, it is more likely a switch to cork occurs, especially in traditionalist countries such as France.
The other controversy is the ‘Cork Taint’, TCA, that occurs when the cork does not correctly seal the wine in. When chlorine comes into contact with specific fungi during the cork making process it creates an invisible taint that is transferred to the wine, causing a range of damp aromas that detract from the wine. Yet the cork producers, Amorim, have recently revealed new methods that will allow an easy removal of TCA from natural cork, a promising solution to ensure cork sealants longevity.
Not so natural corks
Agglomerated/Micro-Agglomerated (technical or composite corks) - A cork-particle board, in which granulated cork dust is bound together tightly by glue or a plant-based binder and pressure. Best for wines that are meant to be drunk young. Can be made TCA free, imparts no flavor, and can control the level of oxygen released into the wine.
Colmated - without premium cork there are crevices left within the sealant, this is filled in with fine cork powder. Has a softer texture and smoother exit out of the bottle. For wines that will age minimally.
Multi-piece - such as Champagne corks where two or more pieces of cork are glued together. Often made from the manufacturer’s bark “scraps.”
Overall, cork is a traditional style of sealant for wines that is still very popular with wine producers and helps create a beautiful and ceremonial atmosphere every time you go to pop open the cork on a delicious bottle of wine.
An aluminium cap, lined with plastic, with an integrated metal skirt hugging the top of a bottle. These screw cap lids for wine bottles appeared on the wine market in 1964, expanding rapidly around the world. The biggest and most popular implementation of screw caps is right here in Australia. Fed up with the low quality corks, Australian winemakers of the 1980s made a big shift to screw caps and haven’t looked back. Corks being phased out by almost every Australian since 2000.
A major positive for the use of screw caps is the price decrease, about a third of the cost of a cork, it provides a better introduction into the world of wine for new vineyard owners and wine producers. Furthermore, not needing to stress over cork taint adds the extra level of peace of mind.
A drawcard for many consumers is the ease of opening a screw top bottle and resealing it after a glass, not having to use a corkscrew and forcing a cork back into a bottle makes the drinking process more seamless than the traditional approach.
Yet, while a big hit in Australia, many other countries view this sealant representative of a cheap wine and lower quality to anything that has a cork. For those with an eco-conscience as well the screw caps are not biodegradable like cork. While recyclable for the most part, they will not break down the same way natural cork bark does. Over time this can have a toll on the natural world, in addition to its high emissions during production.
Up for debate
Living in Australia there is much more debate over cork vs screw cap, in comparison to France in which traditional methods always prevail. Determining which sealant allows the wine to breathe better is a constant discussion, as technology improves more screw caps are developing breathing capabilities, yet not in a natural way that is found in cork.
You will find all our Le Club wines are sealed by corks, coming from small, organic or sustainable vineyards, incredibly aware of both the ecological and traditional elements.