Whisk together the cream and baking soda.
Preheat the sous vide circulator to 180.F. Pour the cream into a bag and remove all air. Cook for 24 hours.
Divide cream between two 12-oz. mason jars and tighten tops until finger-tight. Insert steamer rack into cooker and add 1 in. of water. Place jars on rack, close cooker, and cook at high pressure for 2 hours.