All Port houses strive to uphold the highest standards in quality and bottle their Ports using the best materials available.
Before the late 1990s, the coating on Vintage Port corks used throughout the Port industry was still the traditional type which tended to make the cork adhere to the inside of the bottle neck to a greater extent than its modern equivalent. This had the advantage that the cork provided a very efficient seal. However the higher adherence to the glass, combined with the tendency of the cork to soften or become brittle with time, means that with older Vintage Ports it can be more difficult to extract the cork without it breaking or crumbling.
If the cork does break or crumble when opening, the quality of the wine is unaffected and the filter in a decanting funnel will catch all pieces of cork when decanting.