To make the Strawberry Puree: Wash the berries and cut off the tops. Put the berries in a blender or food processor and blend until pureed. Put the puree in a smallish pot with the 1/4 cup of erythritol and 2 tablespoons of lemon juice, and place over medium heat until it begins to boil and foam. Turn down the heat and simmer until the mixture cooks down to 1 cup. This may take as long as an hour so make sure to stir the mixture about every 10-15 minutes so the strawberries don't burn on the bottom. Cool in the refrigerator.
To make the Balsamic Vinegar Reduction: Pour 1/4 cup of balsamic vinegar into a small saucepan and simmer until it reduces by half. Let cool. 1 teaspoon will be used. The rest can be poured back into the vinegar bottle.
To make the Ice Cream: Make sure all of the ingredients are cold. Add the cooled strawberry puree, heavy cream, buttermilk, erythritol, vodka, vanilla, stevia glycerite and salt in a blender and blend on the lowest speed until mixed. Turn the speed up to medium for just a few moments so the mixture can increase in volume. There should be about 4 cups.
Follow the instructions for making ice cream on your ice cream maker. While the machine is running, add the balsamic vinegar. When the Buttermilk Strawberry Ice Cream reaches the consistency of soft serve ice cream, stop the machine and scoop the ice cream into an air tight, freezer proof container.
Before serving, let the ice cream sit out on the counter for 20-30 minutes to soften.
*** When I buy balsamic vinegar, I buy two bottles and simmer the contents down to the volume of one bottle. The reduction of the vinegar both mellows and intensifies the flavor.Serving size is 1/3 of a cup.