What are Rennet Tablets

The term rennet is often associated with cheese making. Probably, use of rennet is also linked to the origin of cheese making only. Even though there is no conclusive evidence relating to the origin of cheese making, it can be traced back to 8000 BC, when humans started domesticating sheep, goats and cows. It is believed that they stored milk in a bag, which is made from the stomach of a young goat, sheep or cow. The very next day, they discovered that the milk has transformed to solid chunks and liquid whey. They realized that they can preserve milk by curdling it and then drying the solid chunks. This product was later termed cheese. But, the factor that aids in curdling was not identified.

Origin of Rennet
Cheese making continued for decades and at some point, somebody identified that among the four chambers in the cow's stomach, the fourth one called abomasum has a more important role in curdling milk, as compared to the other chambers. It was also noticed that the abomasum of an unweaned (suckling) calf was more active in this process. So, people started preserving the abomasum of unweaned calf by cutting it into small pieces, which were salted and dried. Such small strips of dried abomasum were added to the milk as one of the primary steps of cheese making process. These strips were called rennet. The term rennet is derived from the German word, rennen, which means, 'to coagulate'. Even today, some of the traditional cheese makers follow this method for coagulating milk. But, they prepare a filtered solution from the cow's stomach immersed in saltwater or whey for a stipulated period. Around one gram of this solution is sufficient for coagulating two to four liters of milk.

What is Rennet
Rennet is an enzyme complex, which is produced in the stomach of young mammals. This enzyme complex helps them in digesting mother's milk. This complex consists of many enzymes, like protease, that aids in coagulation of milk, pepsin and lipase. However, the most prominent among these enzymes is chymosin or rennin. Now, you know more about the origin of rennet.

What are Rennet Tablets
The traditional methods of rennet production gave way to the modern ways. Now, cows' stomachs are frozen and milled, before treating with an enzyme extracting solution. Then crude rennet is extracted and is treated with acid. The rennet extract is filtered numerous times after neutralization of the acid. Then it is concentrated to a potency of 1:15000, which means that one gram of this rennet extract can coagulate 15,000 liters of milk. Nowadays rennet extract is available in the form of tablets as well as in the liquid form. Rennet tablets are medium-sized and are whitish in color. Usually, these tablets come in strips and each tablet will be scored into four divisions. As per requirement, whole rennet tablets or its parts are added to milk. It is dissolved in cold water and is then added to the milk. Only cold water is used for dissolving these tablets, as any type of heat can deactivate the enzymes in the tablet. Once the tablets are dissolved, the water is added to the milk, it is left undisturbed for at least 24 hours, as any type of disruption may affect the process of coagulation.

Types of Rennet Tablets
Till the last decade of the twentieth century, rennet was produced through traditional methods. But, later, modern technology was incorporated in this area too. Inadequate supply of cows' stomachs led to the research for alternative methods. Vegetable rennet was made from the enzymes in some plants, but, the most widely used vegetable rennet is made a particular type of mold, called, Mucor miehei. Even though, classified as a vegetable rennet, it is actually a microbial rennet. Another type of commonly available rennet is the genetically engineered rennet, which is made from genetically modified microorganisms, that are made to produce chymosin in large amounts.

There are various brands of rennet tablets available in the market. Try to buy good quality tablets from a good cheese making supply company. You can also purchase it online.