We did not always have the many styles and qualities that we enjoy today. The single biggest development in the advancement Port is the glass bottle. It is the bottle that make vintage Port possible.
Port is one of the most regulated wines made today.
The production area was also the first to be so demarcated in 1756. Each factor is given a numerical value which is then tallied up. As only a certain amount of wine is allowed to be made into Port in any given year, growers are allowed to make a certain amount of Port from their particular vineyards based on the grade they receive. Surplus grapes are usually made into table wine. There are over 90 different varieties of grape permitted to be grown in the Port wine region.