Heat the milk over medium heat while stirring constantly. Once the milk reaches 195°F, remove from heat. Let it cool until the milk reaches 110°F.
Mix the starter Skyr with 1/4 cup of the hot milk, then pour the mixture into the pot of milk while stirring.
Add the rennet while stirring gently.
Cover the pot and wrap in a towel. Let it sit on the counter for 12 hours.
Cut the curd into 1 inch cubes. Put the curds in a colander lined with cheese cloth, which is placed inside a large stock pot. Wrap the cheesecloth around a spoon so that you can lift it up. Place the spoon and cheesecloth on the rim of the stock pot and let it drain while in the fridge for 2-3 hours.
Take out the Skyr, stir until your desired consistency and texture is reached
Top with heavy cream and sugar.