After a year of making various hard cheeses, I finally got a mini-fridge and external thermostat for Christmas and can make my first cams. All my recipes tell me to evenly distribute the curds between four cam molds, but do not tell you how tall the curds should be stacked before draining? Since I have homemade molds (5 1/2" wide Tupperware with the bottoms cut off), I cannot depend on simply evenly distributing the curds. Will they drain down to half their original size? A third? How tall should they be when the have finished draining? Thanks for the help
Typical Cam should be about 4"-4½" diameter hoop - bottomless but with a few weeping holes. The hoops are usually about 4"-5" tall and sometimes that's not enough to fill them up and the cheesemaker has to stop and wait for the level to go down enough to enable topping them off again. The finished cheese in this case is 2"-2½" tall. It's about a third to half the original height.
Your moulds seem bigger though. Going from 4½"x4" to 5½"x4" (for example, don't know your actual size) may seem like a small change but in the world of volume calculations, this is actually a very significant increase, you are going from 63½ cubic inches to 95 - a whopping 150% more. If that's your size than I would remove one mould for every 1 gallon of milk so they will be in good final proportion and not thin discs.
The best way is to calculate the volume. 1 gal milk should give you approx 1 Lb cheese so it's about 2x 250g wheels. With your volume I would use 1.5 gal to make 2 cheeses or 2 gallons to make 3. You have to experiment a bit to get it in the proportions you want.
As for "how do you know when" - you will just do. Initially it shrinks quite fast, slows down after 2 hours and more after 3-4. By the 5-8 hour you will notice that it has kind of stopped draining. Do not be tempted to unmould it as it is still too soft and will collapse. Keep it 12 hours minimum in the mould. Once taken out of the mould and salted it will drain about 20%-30% more volume in the coming 3-5 days.
Good luck!