Hey, Lauren, I too have been happily using Renco dry calf rennet for some time now. I typically use 2, 3 , or 4 gallons in my makes. Never made cream cheese.
A have a set of those 1/8th, 1/16th, and 1/32nd teaspoon measures that I use all the time. Along with george
, I've never used less than 1/32nd tsp. Once you make a few cheeses and see how the milk flocculates, you get a sense for how much rennet to use. Less is more.
Santa was good to me so I now have a digital scale that would theoretically allow me to measure out my rennet in grams as linuxboy recommends. That may be my next endeavor, though the spoons have worked well so far.
For small batches, it's so concentrated that you have to be able to measure out micrograms or dissolve some in water and use up whatever is dissolved within a few weeks. Otherwise, it's excellent rennet.Wait...What!!???.
Dissolve the rennet and then use it up within a few weeks? My tutelage has been make it up (with cold distilled water) just prior to using it and don't let it sit for any length of time prior to its use.