Combine the heavy cream, milk, egg yolks, sugar, coffee concentrate, and salt in a saucepan. Bring to a steep over low-medium heat, but don’t let it boil.

Stir consistently and continue to cook for approximately 8 to 10 minutes until the custard thickens slightly. It should lightly coat the back of a spoon when ready.

Remove from heat then stir in the vanilla extract.

Transfer the custard to a bowl to cool (pour through a mesh strainer if desired). Place the bowl of custard into a larger bowl of ice for about 30 minutes to 1 hour. 

After the custard ice cream base cools to room temperature, cover it with plastic wrap. The plastic wrap needs to touch the top of the custard to prevent a skin from forming.

Transfer it to the refrigerator to cool completely, about 2 hours. Once cooled, the custard has a thin, pudding-like consistency.

Pour the refrigerated ice cream base into the prepared ice cream maker. Churn according to the manufacturer's instructions until the ice cream sets enough to transfer it to a freezer-safe container. It should be firmer than soft-serve consistency.

Freeze until the ice cream is completely firm. (Ours took 8 to 10 hours.)

Serve in a bowl with toppings or in a cone. Scroll up and see the post for tips, FAQs, and storage options.