The Manchego recipe in Ricki’s book says to reduce the 1/2 inch cut curds to the size of grains of rice by stirring slowly with a wire whisk for 30 minutes.
I tried this. Within a couple minutes the curds were fragments the size of grains of sand. After half an hour they were no longer curds at all, and the result was a disaster when put into the press.
Tried it again after slowly whisking the curds for about 30 SECONDS. Much better results.