Cheesemaking (Or, how to waste a gallon of milk)

A few weeks ago I decided that we need to make our own cheese. Every once in a while I get a great idea like this. J is always very supportive. "J," I told her "I think that I'd like to try to make some cheese."
"Really? Why's that?"
"Well, I imagine that fresh cheese tastes delicious. And we'd save money. And it would be healthier. We could spread it on crackers and bread."
She smiled in an "I'm-humoring-you" sort of way and said that if I wanted to give it a try, I was more than welcome.
I called up Calvus (who makes his own delicious bread very successfully) and invited him over. Then I made remarks about rennet tablets to J. She nodded and looked like she wanted to say something. But she didn't. She gets this look sometimes, like when I tell her that I'm going to start waking up earlier to get more reading done, or that I'm going to find a way to organize all of my sheet music.
The evening passed, and I brought up cheesemaking several times the next day as well. J was very patient. I told her that once we'd made mozzarella I'd like to try to make Brie. "We just need 12-18 months and a medium-damp cave."
"Why don't we just see how the Mozzarella goes?" said J.
Two more days passed like this, and then it was cheesemaking day! I stopped at Wegmans on the way home to buy rennet tablets (I got 3 boxes, because I knew that I'd probably be going through rennet tablets quickly from now on.) and I also bought a gallon of milk. I bought 2%, because that's the sort of milk I buy when I'm at the grocery store by myself. If I'm with J, we get 1%, which is a compromise. I didn't actually think at all about whether 2% was the right sort of milk to buy or not...I just got the sort of milk I got while I was out on my own.
Calvus was already at the house when I arrived home, and we immediately poured the milk into a dutch oven (J: Are you sure you should use a dutch oven? Me, totally unsure of what sort of vessel we should use: Yes, we want a dutch oven.) Also, I made a mental note that the biggest pot we have, the one with two small handles, is apparently called a dutch oven.
Once the milk was been poured (irretrievably) into the dutch oven I decided I ought to look at the recipe. Here it is, for anyone who's interested: http://homecooking.about.com/od/cheeserecipes/r/bldairy22.htm (Warning: This recipe doesn't work) Our first step was to dissolve 1/2 rennet tablet into 1/4 cup of cool chlorine-free water.
Calvus: Do we have chlorine-free water?
Me: Nah, I'm sure tap water will be fine.
Next we were instructed to add 2 teaspoons of citric acid.
Me, shouting: J, do we have any citric acid?
J:...I don't think so...
Me: Well, do you think lemon juice would work?
J:....sure.
Following this, we had to wait until the milk reached 88 degrees F and then add our rennet solution. We used a candy thermometer that we suspended from a wooden spoon to carefully monitor the temperature of the mixture. Once we added the rennet solution, we waited for "large curds to appear and to separate from the whey" at 105 degrees F. 105 degrees came, and nothing happened. We let the milk get up to 110 degrees...nothing. We let the mixture sit for five minutes at 105, and nothing happened. We turned up the heat. (I noticed that some of the recipes for other types of cheeses called for hotter temperatures.) Nothing happened. We had a dutch oven full of warm lemony-smelling milk. Calvus left at 5 PM to go to class, and I held out hope for another 15 minutes or so, stirring with a wooden spoon and monitoring the candy thermometer. J was very kind when I flushed the gallon of stinky milk down the toilet upstairs.

If anyone needs rennet tablets, I have plenty of extras.