Vacuum technology methods to study gas permeation through cork stoppers
Does cork breathe? In a bottle of wine, does the gas exchange happens by permeation through the cork, or by lateral leaks that may occur between the cork stopper and the bottleneck?
In this work we applied common vacuum technology methods to study the helium permeation, trough cork stoppers used in wine industry.
First, several bottles were pumped and then were filled with 1 atmosphere of helium. Then bottles were sealed with different types of cork stoppers. The helium permeability was measured by a mass spectrometer leak detector in sniffing mode
The effect of cork compression on gas permeation was also studied by inserting the cork stoppers into cylinders (bottlenecks) having decreasing diameters. The volume from one side of the cork was pumped and filled with 1 atmosphere of helium. The cork stayed in every position (diameter) for several days until a stable reading is achieved and then is moved to a lower diameter. The mass spectrometer leak detector was also used to directly measure the helium flow through the cork stoppers.
Corks having surface treatments showed a better performance when compared with those without. However, the effect of compression was not as pronounced as one could expect. These results will be discussed in this communication.