Well liquor is the "default liquor" used to make a drink. So if you ask for a vodka-cranberry (aka capecodder) without specifying what kind of vodka, you'll get their well alcohol. A bar that uses decent well liquor uses only name brand alcohol. For example, Barton's is not considered a name brand, while Bombay Sapphire is.
Guidelines for good well liquor
- Vodka: Smirnoff or better.
- Gin: Gordons or better. (Bombay or Seagram's gin would be more approriate considering the other choices...)
- Tequilla: Cuervo Gold or better
- Rum: Bacardi or better.
- Whiskey: Jim Beam or better.