Now it is time to begin drying out the curds. This will be done by increasing the heat slowly to 102°F. The heat needs to be increased slowly by about 2-3 degrees every 5 minutes at the beginning. The total cooking time will be 30-45 minutes.
The large curds will begin to form a skin while drying off the exterior, but when the curd is broken it is very soft, wet and tender inside. This is why we take a very long time to dry out the curd. If the skin becomes too firm and thick, as in heating too quickly or stirring too fast, it will be difficult to dry out the inside of the curd. This will result in a wet curd going into the mold and problems in aging. As the curds release whey, the surface firms (as can be seen in the photo at right).
Once the curds are at temperature, they should be stirred in the whey just enough to keep them separated and moving. The bacteria are still developing the needed acidity and the curds will be drying out during this period. This should be done for another 30-45 minutes depending on the dryness of the cheese desired.
During this stirring time, at 15 minutes intervals, allow the curds to settle for a few minutes but do not allow the curds to mat together. Then remove about a pint or two of whey before stirring again.
Stirring these curds in the whey will give them access to the lactose rich whey for further acid development as well as allowing for easier movement of the curds.
The final curds should be cooked well through and should be examined to make sure that enough moisture has been removed. A broken curd should be firm throughout and the curds should have a moderate resistance when pressed between the fingers.
To determine the correct final moisture before removing the whey, a small handful of curds can be taken, compressed into a firm pack, and then pressed with the thumb to see how well they separate.
When they just begin to break with moderate thumb pressure, the cheese will be dry enough to drain.
When this point is reached, the curds can be allowed to settle under the whey for 30 minutes. This will tend to stop the curds from losing more moisture while the bacteria continues to produce acid. It should be stirred every 5 -10 minutes to keep the curds from matting together.