Heat the Milk: In a Dutch oven, combine the milk and vanilla bean paste. Heat slowly over medium-low heat, stirring occasionally to prevent scorching, until the milk reaches 185°F. This should take about 20 minutes.
Cool the Milk: Remove from heat and let the milk cool to 110°F. This is the optimal temperature for culturing.
Prepare the Starter & Rennet: In a small bowl, whisk the ⅓ cup of skyr with 1 cup of the cooled milk until smooth. In another small dish, whisk the 2 drops of rennet into the 2 tablespoons of filtered water.
Combine & Incubate: Stir both the skyr mixture and the rennet mixture into the pot of warm milk. Stir well to fully distribute the cultures and enzymes. Cover the Dutch oven with a lid and wrap it in a thick towel. Place it in the oven with the light on and the door slightly ajar. Let it sit undisturbed for around 8 hours.
Strain the Skyr: Line a colander with double-thickness cheesecloth and set it over a large bowl. Gently spoon the skyr curds into the cheesecloth, cover, and refrigerate overnight.
Whip & Store: The next morning, the whey will have separated, leaving thick skyr curds. Transfer the skyr to a mixing bowl and use a hand mixer to blend until smooth and creamy. Store in airtight jars in the refrigerator for up to four weeks.
