Q. I just made my first cheese - farmhouse cheddar. Everything worked great, and my mold overflowed with curds. However, I tried in vain for several hours to make ricotta from the good amount of whey that I produced.
I carefully heated the whey and watched the temperature religiously right up into the 195-200°F range and held it there, but I never saw more than very tiny little curds precipitate. In desperation, I added a tablespoon of lemon juice, to no avail.
A. Ricotta is comprised of different proteins from the cheese curds. They are released from the whey due to heating.
Those little bits moving out around the rim are your ricotta trying to form. Adding the lemon juice defeated them and the hard little bits you collected were the result. In general, ricotta needs a sweet whey and adding the lemon juice probably made things too acidic.
Patience is important here because it will take about 20 minutes, when at temperature, for them to unite and float to the surface where you can scoop the mass off. Adding more acid and stirring a bit too much will defeat the process.