Rennet Cheese & What is Rennet? (2024)

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Rennet Cheese & What is Rennet? ›

A quick cheesemaking primer. One of the essential ingredients in making nearly every kind of cheese, rennet is a set of enzymes that cheesemakers use to coagulate milk and separate solid curd from liquid whey.

Rennet is the general name for enzymes that act on proteins in milk. It's purpose in a ruminant's stomach is to curdle milk for easier digestion, the same way it curdled our shepherd's drink. Rennet serves the same purpose in cheesemaking: it triggers coagulation. Morgan adds a vial of rennet to a bucket of cold water.

The most widely used rennet substitutes are Miehei coagulant (R. miehei proteinase), Pusillus coagulant (R. pusillus proteinase), and Parasitica coagulant (C. parasitica proteinase).

Most folks are ok with traditional rennet, which is derived from the stomach lining of animals (remember – no animal is ever sacrificed only for rennet). However, some choose to stick with “vegetarian” cheeses, which use plant-based or synthetic rennet to coagulate the milk.

Most hard cheeses, including Parmesan, Cheddar, Manchego, Pecorino Romano, and Swiss, are traditionally made with rennet, while some soft cheeses aren't (scroll down for five you can try). But increasingly, you can find all sorts of cheeses made with non-animal-derived enzymes.

Most stomach-derived rennet is taken from the fourth stomach of young, unweaned calves. These animals are not killed expressly for their rennet; rather they are killed for meat production (in this case, veal) and the rennet is a byproduct.

The lemon juice, vinegar and citric acid can coagulate the milk without rennet but frequently work best with hot milk.

Rennet comes from an organic substance that contains the enzyme rennin. It's mainly found in the lining of the fourth stomach of young goats, calves and lambs. It only occurs in these animals when their main diet is still milk.

Adding citric acid to milk instantly adjusts the pH so that it's ready for rennet, in the case of mozzarella and burrata. In whole milk ricotta, the combination of acid and heat works to coagulate the curds without rennet.

In 1984 after 7 years of perseverance, Beauty Without Cruelty managed to convince the Government of India to impose a total ban on the import of animal rennet used in cheese-making. As this ban still exists, all Indian-made cheese is vegetarian.

Is rennet removed from cheese? ›

Rennet from calves has become less common for this use, to the point that less than 5% of cheese in the United States is made using animal rennet today. Most cheese is now made using chymosin derived from bacterial sources.

Too much rennet was used or too much butterfat, left your cheese during the process. Rubbery cheese can happen when an excess amount of rennet is used, too much rennet equals a rubber ball, too little, soup!

You can make rennet from quite a few wild plants. It is slower acting that shop-bought rennet and usually needs to be left overnight to curdle the milk. The best plants are nettle, sorrel and thistle.

(You can safely buy fresh cheeses that don't contain rennet at all: think cream cheese and paneer.) At the supermarket? Trader Joe's and Whole Foods both label the source of rennet used in their generic-brand cheeses, many of which are vegetarian.

Rennet is made of enzymes that are found in the lining of un-weened mammal stomachs, usually from a cow (calf), sheep (lamb) or goat (kid). Young mammals' main source of food is milk.

Vegetable rennet, microbial rennet, and certain forms of fermentation-based rennet are considered vegetarian. Rennet is sold in several forms. Liquid rennet is often used when making smaller batches of cheese, as it's easy to measure.

If you're wondering does mozzarella cheese have Rennet, the answer is both yes and no. You can pick an animal-based or plant-based mozzarella. In contrast, rennet-free mozzarella cheese has a mild flavor and a soft texture ideal for creating panini or pizzas.

Calf rennet is a mixture of milk clotting enzymes extracted from the abomasum, or 4th stomach, of baby calves. You may be saying “Hey, I thought rennet was the enzyme. Rennet's a mixture of enzymes?” This discrepancy stems from the discussion of definitions in the opening paragraph of this post.