It was first made in Italy and therefore is classed as an Italian cheese. The basis of traditional ricotta manufacturing process is the coagulation of whey proteins by heat. The usual raw material is whey from cheddar, Swiss, Mozzarella or other hard cheese. . Ricotta cheese is now prepared from whole milk with or without addition of whey.
Most of the ricotta production is confined to a batch process. It is common to blend 10-25% milk to neutralize acid in the whey, enhance yield and curd cohesiveness. The mixture is heated in a kettle to 82-93 °C, followed by the addition of a food –grade acid such as lactic, acetic or citric acids in quantity enough to drop the pH of the mixture to 5.9 – 6.1.
Vinegar, citric acid solution or sour whey may be used as an acidulant for sweet wheys.
The mixture is held for 15-20 min, after which the curd is dipped with a perforated ladle and collected in a muslin bag.
The bag is allowed to drip and cool in cold temperature. Alternatively, the curd is drained in perforated stainless hoops and allowed to dry. Salt and lactic starter bacteria may incorprrated into the draining curd and it has cooled to 30 ° C. Lactic acid starter is to improved the flavor and promote ripening,
The dried curd may be packaged into plastic bags or cups for marketing as ‘fresh’ ricotta, or it may pressed to produce dry ricotta.
The curd is soft, fragile and grainy, and may be pressed slightly to achieve cohesiveness. If it is to be marketed as fresh or moist, draining is continued or the curd may be pressed for several hours in cheesecloth-lined hoops, then it is packed in paper cartons that usually hold 5 pounds.
Ricotta produced by the traditional method is very susceptible to spillage by yeasts, molds, and bacteria and hence has a relatively short shelf-life 1 to 3 weeks at 4 °C.
Significant advances have been made in the automation of ricotta cheese production with the objective of improving curd separation, cheese yield and shelf life.
Ricotta cheese processing