Does anyone have a mozzarella recipe that produces soft cheese?

I made one with rennet and citric acid and it produced a dense and rubbery cheese. I used raw whole milk. The ratio I used was 1/4 rennet tablet to 1 gallon of milk with 1 tsp. of citric acid...it was a recipe from New England cheese making. It was perfect up until it came out of the brine on day two....does anyone know why it turned out hard and rubbery and have a different recipe?