The Ostkaka recipe must use unpasteurized milk or the rennet will not work. Milk from a fresh cow is the best. The first useable milking contains colastrum and sets quickly. Grandmother would make it without using rennet if she had fresh cow milk.

4 qts. fresh whole milk
3/4 c. flour
1/2 rennet tablet
1/2 c. cold water
3 eggs, beaten
3/4 c. sugar
1/2 tsp. salt
1 1/2 c. cream
1/2 tsp. almond