The properties of cork

Used since Antiquity as a closure for Greek amphorae, cork has specific properties which make it a unique material. Well-known for its elasticity, it also boasts other, very worthwhile physical characteristics that make it an ally for wine maturation.

Elasticity, cork’s major advantage

Cork is extremely shock- and pressure-resistant due to its high level of elasticity. It therefore has a great ability to return to its original shape, just like a memory foam cushion.

When pressure is exerted, even strongly, it instantly resumes 85% of its initial volume.

This elasticity is highly sought-after in the bottling sector but also in the building industry.

The 10 other properties of cork worth knowing

Although cork’s elasticity is its best-known quality, as a raw material it has other properties that are just as interesting.

Cork is:

  • Watertight ;           
  • Has low permeability to air and gases ;    
  • Light ;
  • Rot-proof ;           
  • Health-neutral ;           
  • Fire-resistant ;       
  • Stable because it is chemically neutral and does not react in contact with acid, for instance ;       
  • Insulating (thermal and sound) ;     
  • Resistant over time ;
  • Environmentally-friendly because it is a natural material that does not involve felling trees and is recyclable.

The properties of cork of benefit to wine

Its elasticity, but also all of cork’s other properties, make it an excellent material for producing closures for bottles of wine.

Cork is watertight, allowing the closure to properly seal the bottle and avoid any wine spillage. But it does allow small of amounts of air through.

And oxygen is a crucial component for wine to mature well in the bottle.

When temperature and hygrometry are optimal, the porosity of cork allows the wine to breathe and mature harmoniously.

Also, cork closures exert strong and consistent pressure on the surface of the bottleneck and can therefore compensate for any imperfections in the glass bottle. This is also what makes each cork closure unique.

Cork’s properties make it a unique material, which explains why it is so successful. The cork closure is still extremely sought-after in the wine industry and offers the perfect combination of watertight seal and the required oxygenation of the wine to allow it to breathe and mature.