Pot Cheese vs Ricotta Cheese?
What is the difference between pot and ricotta cheese? And why is pot chesse used in blintzes while ricotta cheese is used in stuffing pastas?
Pot cheese is a variation of cottage cheese. To make cottage cheese, you basically curdle milk with vinegar or another souring agent and let the curds drain naturally without pressing them. Some of the whey remains with the cheese, giving it a soft, moist texture. To make pot cheese, you press some of the whey out mechanically. Going further, you can expel even more whey and you wind up with farmer cheese, which has the firmest, driest and most crumbly texture of the three.
True ricotta is made by a different process. When milk is separated into curds and whey, most of the protein in the milk (primarily casein) passes into the curds. However, there are also proteins (mostly albumin) that remain in the whey. The acidified whey is then heated to a high temperature--near boiling. This causes the protein to change structure and precipitate out. What you wind up with is ricotta. It is a low yield cheese, because there isn't that much protein in the whey. Ricotta means "cooked again" in Italian. The first cooking is heating the milk/curds for the original cheese (often Pecorino Romano) and the second cooking is heating the left over whey to make ricotta.
I used the term "true ricotta" above, because other methods have been devised for making ricotta-like cheese directly from milk (rather than whey), which is what commercial dairies and some home cheesemakers do. Strictly speaking, it isn't ricotta, because there aren't two separate heating/cooking steps. When made from whole milk instead of whey, ricotta more closely resembles cottage cheese, although the milk used for ricotta is heated to a higher temperature. Also, ricotta tastes sweeter because of the lack of salt compared to cottage cheese.
As for the difference between blintzes and stuffed pasta--different countries of origin, different traditions of cheesemaking.