Warm half and half, sugar and salt in a medium saucepan over medium heat, whisking to dissolve sugar.
Beat egg yolks in a small mixing bowl, add ½ cup of the warm mixture to the egg yolks and whisk to combine. Then add that mixture to the half and half on the stovetop.
Whisk in coffee granulates until dissolved.
Cook over medium-low heat stirring constantly until the mixture thickens slightly – just barely sticking to the back of a spatula or until it reaches 170 degrees F.
Place the heavy cream into a bowl with a fine mesh strainer on top of the bowl.
Strain the custard into the heavy cream. Discard what is left on the strainer.
Add vanilla extract, stir to combine.
Transfer to an airtight container and cool completely in the fridge (preferably overnight).
Pour mixture into an ice cream maker and churn until frozen (about 30-40 minutes).
Transfer to an airtight container and freeze completely, about 4 hours.
