01 - Combine whole milk, heavy cream, half the sugar, and salt in a medium saucepan. Heat over medium heat until just steaming, avoiding boiling.
02 - Whisk egg yolks with remaining sugar in a separate bowl until mixture becomes pale and thickened.
03 - Gradually pour 1 cup of hot milk mixture into yolks while whisking constantly to temper eggs and prevent curdling.
04 - Return yolk mixture to saucepan. Cook over medium-low heat, stirring continuously with wooden spoon until custard thickens and coats back of spoon, reaching 170–175°F.
05 - Remove from heat. Stir in brewed coffee, instant espresso powder, and sweetened condensed milk until completely blended.
06 - Strain custard through fine-mesh sieve into clean bowl. Cool to room temperature, then cover and refrigerate until thoroughly chilled, at least 4 hours or preferably overnight.
07 - Process chilled custard in ice cream maker following manufacturer's instructions until mixture reaches soft-serve consistency.
08 - Transfer churned ice cream to airtight container. Freeze for minimum 2 hours to achieve firmer texture before serving.