Not only does climate change effect our water, soil and therefore our grapes, it also has had an effect on our wine materials, more specifically, corks.
Weather patterns have been continuously shifting with volatile seasons and a steady increase in temperatures throughout the world.
Wine bottle corks are created by the protective outer layer of bark surrounding the quercus suber oak trees, which grow only in southwest Europe and northwest Africa. As if late, corks have not been as high performing due to weather changes, that cause the cork bark to become thinner and thinner.
A group of researchers at the University of Lisbon analyzed the composition of high-performing trees and low-performing trees. They came to the conclusion that the difference between them was that the high-performing trees had heat shock proteins, which are compounds that help the higher performing trees deal with environmental stresses such as drought and high temperature spikes.
The low-performing trees had lower levels of these heat shock proteins causing them to produce thinner bark (which cannot be used for higher quality corks). Due to the low levels of the compound plus the addition of phenolic compounds that show up in response to weather and environmental stress, the cork itself therefore has more lenticular channels.
These channels are very undesirable in wine corks as they have a high tendency to let oxygen through, therefore causing a bottle to become corked. A great and intact cork will safeguard a wine’s taste while aiding in its aging process while these thinner corks can and often do taint a wine’s flavor.
This new development poses some issues to the cork industry that already face concerns due to companies creating alternative closures to wine bottles already, such as synthetic wine stoppers or metal caps. Problems have arisen with both of these alternatives; screw caps are not sustainable and are therefore not biodegradable while the plastic closures are made from petro-chemicals, also not biodegradable.
There has been talk of cloning the trees with the high levels of protein, or adding protein supplements to the low-yield trees. This type of solution wouldn’t come into fruition for another decade or so as a cork oak needs to be 25 years old before it can produce an annual cork harvest.
With a steady decline in cork production, we will see an increase in prices forcing the wine industry to move to cheaper alternatives. Therefore, wineries may start looking to move away from the cork altogether for the long term.
So, are you stuck on the highly desirable cork, or will you move to a newer alternative?