In a medium saucepan, add 2 cups of fresh organic cranberries, 1/2 cup of your chosen low-carb sweetener, and 2 cups of water. Over medium heat, bring the mixture to a gentle boil, stirring occasionally.

Reduce the heat to low and let the cranberry mixture simmer for about 10 minutes. Using a potato masher, gently mash the cranberries while they cook to help release more flavor.

Remove the saucepan from heat and strain the mixture through a fine mesh sieve into a bowl, pressing down on the solids to extract as much liquid as possible.

Once strained, stir in 1/4 cup of freshly squeezed lemon juice into the cranberry concentrate.

In low-ball glasses, add 2 tablespoons of the cranberry-lemon concentrate, fill each glass with ice, and top off with sparkling mineral water.

Garnish each spritzer with a few fresh cranberries or a slice of lemon. Serve immediately.