Freeze the ice cream drum in the freezer for at least 24 hours before attempting to make ice cream.
Before you begin to cook the ice cream base, place 250 mL (1 cup) of the cold whipping cream in a 1 L (4 cup) measuring cup. Set a strainer over top. Set aside
In a large bowl, whisk the egg yolks with half the sugar until the mixture is a very pale yellow and very light.
In a medium saucepan, whisk the rest of the sugar with the milk, the remaining 125 mL (½ cup) of the cream, the lemon juice, the lemon zest, and the salt. Heat the mixture until it is very hot and almost comes to a boil.
Pour the hot milk mixture over the whisked yolks to temper the eggs. Whisk continuously until the mixture is homogenous, then transfer it back to the saucepan.
Switch to a wooden spoon and, stirring constantly, heat the mixture on the stove over medium—low heat until the lemon custard has thickened and has reached 83 ºC (181 ºF).
Pour the mixture over the strainer, gently pushing the custard through, if need be.
Cover with plastic wrap, then refrigerate the lemon custard base for several hours to cool completely (overnight is best!).
Place the frozen drum on the ice cream maker, and churn the custard according to instructions. It can take over 15 minutes to churn the ice cream.
When the ice cream has reached the desired consistency. Turn off the machine, disassemble, and transfer the ice cream to a container. Place in freezer for a few hours to finish chilling.