• A term often heard for high-quality coffee is degree coffee. Milk certified as pure with a lactometer was called degree milk owing to a mistaken association with the thermometer. Coffee prepared with degree milk became known as degree coffee[citation needed].
  • Another explanation for degree coffee is that chicory beans were used to make the coffee. The South Indian pronunciation of chickory became chigory then digory and finally degree.
  • Yet another explanation is that, when coffee is decocted for the first time, it is called as the first degree or simply as the “Degree Coffee”. This has the strongest flavour and the necessary strength to mix with milk without watering down the taste. In less affluent households, in earlier days, coffee was decocted for a second or third time from the same initial load; this became the second degree coffee and naturally, is not as strong. Affluent households drank first degree or the famous “Degree Coffee” only.

–from the Wikipedia entry on Indian Filter Coffee.