Suberin (45%) - the main component of the cell walls; responsible for the resilience of the cork
Lignin (27%) - the binding compound
Polysaccharides (12%) - components of the cell walls which help define the texture of the cork
Tannins (6%) - polyphenolic compounds responsible for colour
Ceroids (5%) - hydrophobic compounds that ensure the imperviousness of cork
Mineral water, glycerine, and others make up the remaining 4%.
GBL can cause some deterioration and wear to the cork. Use glass vials with ground glass stoppers for maximum storage longevity.