Add the cream to the bowl of a stand mixer. Beat on medium speed until starting to thicken, about 8 minutes. You want to avoid incorporating too much air so keep the speed lower than you would to make whipped cream.
Add the lemon juice, zest, beer, sugar, and salt to a small bowl. Stir until the sugar has dissolved.
While the mixer is running, slowly add the lemon juice mixture until well combined with the cream. The acid from the lemons will help thicken the cream.
Slowly add the sweetened condensed milk until well combined.
Add to a freezer safe container. Freeze for at least 6 hours before serving.