Whisk the heavy cream, 3/4 cup red wine and granulated sugar together in a saucepan over medium heat. Allow to simmer for approximately 10 minutes, stirring constantly.
Remove from heat and add chocolate, butter and salt. allow to sit for five minutes, then stir until smooth.
Add 1/4 cup remaining red wine and stir until incorporated and smooth.
Ganache will thicken as it cools.
Notes
Cover and store leftover ganache in the refrigerator for up to 14 days.