I modified this cheese from one I learned from "Joyce" on the Lactobacillus Board on the web. It makes an "American mozzarella" similar to what is used on American pizza. It is very elastic, melts well and strings when hot. (It is not, however Italian mozzarella which is more tender at room temperature and possesses a more subtle flavor.)  If you would like to make the Italian version, here is a  recipe for making Italian fresh mozzarella which, as you will see is more complex than this one for "American" mozzarella.

The links within the recipe are to my video page on which you will see clips of the "clean break," and "cutting the curd."

EQUIPMENT:

1 cup pyrex measuring cup
2 cup pyrex measuring cup
5 quart pot, stainless or enamel, with cover
Small skillet (2 inches smaller than diameter of above pot)
Thermometer, -20 to 110C
Sterile fine-weave dish cloth
8 inch strainer
1000 watt microwave oven

INGREDIENTS:

1 gallon milk (I used cow's milk, homogenized, pasteurized, 3.5% butter fat)
1¼ teaspoon citric acid powder (from local pharmacy) dissolved in ½ cup cool water
½ tablet Junket rennet (from local supermarket) suspended in ¼ cup cool water

1. Dissolve 1¼ tsp. citric acid powder into ½ cup cool water. Add to milk and stir well. Heat milk to 31C (88F) over boiling water in a small skillet.
2. Dissolve ½ tablet Junket Rennet into ¼ cup cool water. Stir thoroughly into warmed milk mixture. Let set undisturbed for 1-2 hours, until a clean break is achieved.
3. Cut curd into ½ inches cubes.
4. Over low heat, stir the curds and whey gently to keep the curds separated and temperature uniform until temperature reaches 42C (108F). Hold at 42C (108F) for 35 minutes, stirring every five minutes to keep curds separated and off the hot bottom.
5. Collect curds by pouring curds and whey through a fine cloth held in an 8 inch sieve over same covered container, let drain for 15 minutes. Save whey to make ricotta (bring liquid to 95C, cool, filter particulates).
6. Break up curd, thoroughly mix in 1 teaspoon salt.
7. Place 1 cup salted curd into 2 cup measure.
8. Microwave on high (1000 watts) for 45 seconds (adjust the time so that you get the desired elasticity). Separate hot curd from container with the back of a fork, knead with hands to distribute heat evenly. Stretch and fold to make smooth and elastic, shape into a soft ball, pinch, place in refrigerator to solidify.