Inspired by the minimalist elegance of Masa's famed dessert, this recipe allows home cooks to recreate a rich, vibrant, and perfectly balanced matcha ice cream that captures the essence of high-end Japanese indulgence.
Prepare an ice bath: Fill a large bowl with ice water and set a smaller bowl (or a fine-mesh sieve over a bowl) inside it. Have a strainer ready.
In a medium saucepan, combine heavy cream, whole milk, 1/2 cup of the granulated sugar, and salt. Heat over medium heat, stirring occasionally, until the mixture is steaming and small bubbles appear around the edge (do not boil). Remove from heat.
In a separate medium bowl, whisk together the egg yolks and the remaining 1/4 cup of granulated sugar until light in color and creamy.
Slowly temper the egg yolks: While whisking constantly, gradually pour about 1/2 cup of the hot cream mixture into the egg yolk mixture. This slowly raises the temperature of the yolks without scrambling them. Once combined, pour the tempered yolk mixture back into the saucepan with the remaining hot cream mixture.
Return the saucepan to medium-low heat. Cook, stirring constantly with a rubber spatula or wooden spoon, until the custard thickens enough to coat the back of the spoon (it should reach about 175-180°F / 79-82°C). Do not boil.
Immediately pour the custard through the fine-mesh sieve into the smaller bowl set in the ice bath. Stir occasionally until the custard is cool. If using, stir in the vanilla extract.
Sift the matcha powder directly into the cooled custard base. Whisk thoroughly until completely dissolved and no lumps remain. For an extra smooth finish, you can use an immersion blender or whisk very vigorously.
Cover the custard and refrigerate for at least 4 hours, or preferably overnight, until thoroughly chilled. This is crucial for texture.
Once chilled, pour the custard into your ice cream maker and churn according to the manufacturer's instructions (typically 20-30 minutes), until it reaches the consistency of soft-serve ice cream.
Transfer the churned ice cream to an airtight container and freeze for at least 2-4 hours, or until firm, before serving. For best texture, let it sit at room temperature for 5-10 minutes before scooping.