In a medium saucepan, combine half and half, sugar, and salt. Whisk constantly over medium heat until the sugar has fully dissolved.
In a small bowl, beat egg yolks until smooth.
Slowly pour ½ cup of half and half mixture into the egg yolks, whisking constantly. Mix until combined.
Pour egg yolk mixture into the saucepan with the remaining half and half mixture. Stir well.
Stir in Delgada Instant Coffee until completely dissolved. Continue to stir until the mixture thickens, reaching 170°F.
In a large bowl, combine heavy cream and vanilla extract. Gradually add in the coffee mixture and stir until well combined.
Transfer mixture to an airtight container and refrigerate until completely cooled. (For best results, chill overnight!)
Pour mixture into an ice cream maker. Churn for 30–40 minutes.
Transfer churned ice cream to an airtight container. Freeze for at least 4 hours, or until completely firm.
Enjoy a smooth, creamy scoop of Delgada ice cream!