Add milk to a large pot. Thoroughly stir in the dissolved calcium chloride. Heat the milk to 90 degrees, stirring.
Add the mesophilic culture and stir until melted. Cover the pot and allow to sit and ripen for 45 minutes.
Add the dissolved rennet, stirring for one minute in a gentle up & down motion. Cover the pot and allow to sit forming curds for 45 minutes.
Test for a clean break by using a knife to just lift a bit of the curd. It should lift clean and smooth and the void should fill with a bit of whey.
Cut the curds to 1/2" cubes. Allow to sit and heal for 5 minutes.
Indirectly heat the curds to 100 degrees, aiming for a rate of 2 degrees every 5 minutes. This is achieved by placing the pot in a sink of hot water (100-110 degrees) and stirring frequently. It will take about 45 minutes. Curds will shrink up a bit and the yellow whey will increase. I have also found it necessary to drain a bit of the water in the sink and refill it with boiling water. Stir the pot occasionally (and gently) to keep the curds from matting.
Once the pot reaches 100-degrees, cover it and let sit for 5 minutes.
Scoop the curds into a cheesecloth lined colander. Tie up the cheesecloth and hang for 1 hour.
Take down the cheesecloth and break the curds apart with your fingers.
Mix in 1 T. of salt, 1/2 T. at a time, waiting 1 minute between each addition.
Place in cheesecloth lined press and press for 30 minutes at 4-5 pounds of pressure.
Take the curds from the press, removing the cheesecloth. Put the cheesecloth back into the mold and return the curds to the mold upside down. Press at 10-12 pounds for 1 hour.
Remove and turn cheese again and press at 20-25 pounds for 12 hours.
Remove cheese from press and unwrap. Air dry for 2 to 4 days, turning twice a day. Cheese is ready when a butter colored rind develops and is dry to the touch.
To age the cheddar, seal in wax for up to three months and store at a temperature of 45-60 degrees.