Final answer:
The sweet fortified wine named Rutherglen from Australia is made from the Muscat grape, specifically the Muscat à Petit Grains Rouge variety, known for producing wines with rich flavors and a luscious sweetness.
Step-by-step explanation:
The grape that is used to make the sweet fortified wine known as Rutherglen from Australia is the Muscat grape, specifically the Muscat à Petit Grains Rouge variant.
This grape variety is renowned for its potential to produce richly flavored, sweet wines that are often fortified to increase their alcohol content and to stabilize the wine for long aging.
Rutherglen Muscat is highly prized for its complex flavors of dried fruits, caramel, and spice, combined with a luscious sweetness and a smooth finish.