1In a medium saucepan, combine half and half, corn syrup, ¼ cup sugar, coffee beans, vanilla bean paste and salt.
2Heat over medium heat, stirring occasionally, until a candy thermometer registers 170-degrees, remove from heat, and strain out coffee beans.
3In a medium bowl, whisk together egg yolks and remaining ¼ cup sugar. Add 1 cup warm half and half mixture to egg mixture, whisking constantly to temper egg yolks. Add egg mixture to the remaining half and half mixture, whisking to combine.
4Return to heat and cook over medium-low heat, whisking constantly, until candy thermometer registers 180-degrees, 7 to 10 minutes. Immediately pour custard into a large bowl and let it fully cool to room temperature.
5Transfer ice cream base to freezer for 30 minutes.
6Pour base into ice cream maker and churn until soft serve consistency, about 10 to 20 minutes.
7Transfer ice cream to a metal loaf pan or cake pan and place plastic wrap directly on surface. Freeze until solid, ideally overnight, before serving.
Notes: Follow equipment instructions for ice cream maker. Home ice cream machines usually require pre-freezing the churning chamber. Industrial makers will freeze the base in about 10 minutes.