|Whipping cream||250 Milliliter (1 cup)|
|Cultured butter milk||30 Milliliter (2 Tablespoon)|
1. Heat cream in small saucepan over medium-low heat just until barely warm to the touch (90 to 100°F or 32 to 38°C); transfer to clean bowl or jar.
2. Stir buttermilk into cream. Let stand at warm room temperature, covered with plastic wrap, until cream begins to thicken, 8 to 16 hours.
3. Stir cream until smooth. Refrigerate, covered, at least 1 day to allow tart flavor to develop. Mexican Cream can be stored in refrigerator up to 2 weeks.