Port is sweeter than Sauternes.
The sweetness difference between Port and Sauternes seems like a fitting topic this time of year when people often end a holiday meal with something luscious and sweet. As it turns out, Port is considerably less sweet than Sauternes. Port has about 7% residual sugar (and is fortified to about 20% alcohol). Sauternes, on the other hand, rings in at 10 to 15% residual sugar (and is generally 13-14% alcohol).