Grandpa Roys Caramel Ice Cream Recipe

Cook sugar and salt in a dry 4- to 5-quart heavy pot over moderate heat, undisturbed, until it begins to melt. Continue to cook, stirring occasionally with a long-handled wooden spoon, until sugar is melted into a deep golden caramel, 10 to 12 minutes.
Carefully pour in cream (caramel will harden and steam vigorously). Simmer over moderately low heat, stirring occasionally, until caramel is dissolved. Whisk in milk and return just to a boil, then remove from heat.
Whisk together yolks and corn syrup in a large bowl until smooth, then add half of hot caramel cream in a slow stream, whisking until combined well. Add yolk mixture in a slow stream to caramel cream in pot, whisking, then cook over low heat, stirring constantly with wooden spoon, until mixture is thickened and thermometer registers 170 to 175°F, about 3 minutes.
Immediately pour caramel custard through a fine-mesh sieve into a metal bowl set in a larger bowl of ice and cold water. Cool to room temperature, stirring occasionally, about 20 minutes.
Remove custard from ice bath and chill, covered, until cold, about 1 hour. Freeze in an ice cream maker, then transfer to an airtight container and put in freezer to harden, at least 4 hours.
Sprinkle scoops of ice cream with sea salt if desired.