Is there any other difference between a ruby port and a tawny port than the difference in colour?
The main difference is how they are aged. “Ruby port is the cheapest and most extensively produced type of port. After fermentation it is stored in tanks made of concrete or stainless steel to prevent oxidative aging, and preserve its rich claret color. The wine is usually blended to match the style of the brand to which it is to be sold. The wine is fined and cold filtered before bottling, and does not generally improve with age.” Tawny ports are wines made from red grapes that are aged in wooden barrels, exposing them to gradual oxidation and evaporation. As a result, they gradually mellow to a golden-brown colour. The exposure to wood imparts “nutty” flavours to the wine, which is blended to match the house style.