- Add egg yolks and sugar to a medium saucepan and whisk until a light yellow color and well combined. In another small sauce pan, heat milk over medium-low heat until it just begins to simmer. Gradually add milk to egg and sugar mixture, stirring constantly. Return to heat until it reaches 165º F.As soon as it reaches the correct temperature, remove it from the heat. Pour custard base into an airtight container and store in the refrigerator. Once the custard base is ready, stir in the heavy cream and vanilla extract and pour it into your ice cream maker and serve chilled.