10 Things to Know About Rennet [It's in your cheese]

We recently received an interesting inquiry from a Fooducate community member:

I just learned what “rennet” is (an enzyme used to make most cheeses and which is usually derived from the lining of calves stomachs).  You can imagine what an unwelcome surprise this might be to some people.

For example, I do not eat 1. Red meat and 2. Baby animals of any kind.

So now I am looking for products, especially cheeses, which are made with “vegetable” rennet.

My question is “what more do I need to know”? Where else in the food world does the ingredient  “enzymes” mean “stomach linings” or similar?  What is vegetable rennet made from?  Hope you can help.

What you need to know:

1. Cheese has been manufactured using rennet for thousands of years, mostly in Europe.

2. Indeed, rennet is extracted from the lining of the inside of the stomach of mammals, and most commonly from the fourth stomach of young calves.

3. Rennet contains enzymes that cause milk to become cheese, by separating it into the solid curds and the liquid whey.

4. Different animal rennet are used as well to create other types of cheese.

5. Most cheese in the US is NOT manufactured using rennet, mostly due to the availability of cheaper alternatives.

6. Vegetable rennet is made from certain vegetables that have coagulation properties as well. Thistle is the most common form.

7. Microbial rennet is derived from molds. Yum. A side effect is a slightly bitter tasting cheese.

8. Genetically engineered rennet is derived from plants that have been injected with cow genes.

What to do at the supermarket:

9. Companies are not legally required to disclose the source of the rennet, so unless the product specifically states a non-animal source for rennet, you won’t know.

10. Another way to verify that the rennet is not from an animal source is to look for a kosher symbol. According to Jewish dietary laws, milk and meat ingredients cannot be mixed or eaten at the same time.

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  • http://twitter.com/cortado Rune Smistad

    It is as easy as this: Cheese is made with rennet. If not, it is something else, a substitute. It’s like a veggie burger.. It´s not a burger, but looks liek one. Eat real food, come to Europe!

    • on: orbit

      come to central-coast California and enjoy the very cutting edge of healthy cuisine… (:

    • Enric Martinez

      Sorry to crash your ego-trip mate, but here in the good’old EU (Holland here) we use almost exclusively genetically engineered rennet… that is actually a mold, not vegetables with cow genes, it’s commercial name is Chymosin (https://en.wikipedia.org/wiki/Rennet#Fermentation-produced_chymosin_.28FPC.29).

  • Amy in Colorado

    I don’t eat red meat or baby animals either. Makes me vomit, actually. If it can be derived from vegetables, why slaughter innocent animals? The food industry is disgusting, inhumane, and greedy here and in Europe and most people aren’t aware of what’s going on. Thank you very much for the tip!!


      As a believer, I was grieved in my soul when I read this. Not because of you in particular, but because I wondered how many people who were grossed out at the thought of eating baby animals wouldn’t think twice about sacrificing an unborn child on the altar of convenience.
      Surely our nation will be judged for our sins.
      Repent while there is yet a little time.

      • tom

        Well, if you eat factory farmed chicken, pork or beef, you’re eating infant/young teenage animals, not sure whether it’s much better than eating babies…


        Really, Tom? I hope you were exaggerating.
        Mostly I eat chicken, and judging from the size I’d say they’re full grown.

        • LuBabaChica

          My dog is fully grown. It doesn’t mean that he is not still young.. In a natural environment, chickens
          would live for seven years. The vast majority of those
          destined for the table live for six to seven weeks in windowless sheds shared with thousands of other
          birds. Stop being ignorant.


            I’m ignorant? Because I have a different opinion about eating meat?
            Or because in my original post I dared say something against people who wouldn’t think twice about having an abortion,but get squeamish about eating meat and killing animals? It was about hypocrisy.

          • jo

            Whos saying we wouldnt think twice about killing babies? Your choices have an affect on many things. Not you in particular, in general. Both topics are very sad indeed. It is a personal choice, therefore no one should be taking comments personally. I choose not to eat the flesh of animals. It is because I have been awakened to the atrocities of factory farming. I know the difference with animals & humans but I choose not to support the exploitation of animals. Thats just me. Im not speciesist. Im no better than you. Just a personal choice.

          • Enric Martinez

            What is actually your point? Are you sad because they throw away the abortions and don’t make burgers out of them?

          • Aquaria

            Your genocidal filth religion’s banning of abortion would cause millions of those pweshus babeez to be born and starve from lack of resources to care for them, while also causing millions more women to be maimed or die from complications of pregnancy and childbirth, often taking your pweshus babeez along with them, genocidal scum moron.

            Women are at least 10 times more likely to die from having a baby than having an abortion, a fact you genocidal filth peddlers refuse to face.

            That’s why people with brains know that your real concern isn’t the babeez, but in making sure that women–and ONLY WOMEN–suffer and die for having sex. You can’t stand the idea of anyone having, never mind enjoying sex, you sexist, genocidal hatemongering scum.

            You don’t fool anyone, christfilth.

          • b2c

            Neither do you, God hater.

          • god hater

            You can’t hate god, for he is not real!

          • Nova

            Lady you’ve list the plot

        • jo

          Full grown by antibiotics.

          • Me

            No, by hormones.

      • Enric Martinez

        Ever heard about a logical figure called “Straw Man Fallacy”? Nope? Check it out, you may find it extremely educative

    • andre laforest

      I am from quebec canada and i think like you.

    • Ad

      But if I understand well the vegetable rennet is genetically made that means from laboratory = no real food. It is that right??

  • http://twitter.com/awakewellness Rachel Assuncao

    Didn’t know about genetically modified rennet. Yet another reason to eat organic. Thanks for the informative post!

    • Aquaria

      Yes, eat organic, so that you can exponentially increase your chances of getting salmonella, e coli, botulism and ptomaine. Worse, enjoy your exposure to pesticides even worse than the commercially grown products.

      The gene pool could do with less stupid.

  • only local meet

    If you’re going to eat meat at all, why are you making those distinctions?

    If you’re going to eat meat, why not make it locally sourced, humanely raised meat?

    Not eating red meat & not eating baby animals is like saying you’re going to reduce your carbon footprint by trading in your Humvee for an SUV.

    @Rune Smistad: not all cheese is made with rennet. Many soft cheese such as mascarpone, ricotta, (some) cream cheese and cottage cheese use an acid as a coagulant. And there are cheese making traditions that favor vegetable rennets.

    • FrugalArugula

      Excuse me, but not eating red meat/baby animals is a choice and has nothing to do with humvees or SUV’s or really anything to do with the environment, though it is statistically proven to do more than that ridiculous comparison.

      I gave red meat up many years ago and have found ZERO reason to reincorporate it into my diet. So few places are doing humane anything. Most likely, EVEN LOCAL MEAT has animals slaughtered at a USDA approved industrial facility. Basically, that says to me that the happy lives and excellent dietary conditions of said animal are then thrown straight into the same squalid conditions everything else gets killed in.

      SO. That said, I love cheese. Real cheeses. From time to time, you’ll see “animal rennet,” sometimes it’s “vegetable rennet” and other times it just says “rennet.”

      I’ve battled with this for a long time over if I care. When I’m already eating cheeses from some small farm in god knows where…that costs me $26.95 a pound. I do my best to keep everything I eat “local” or at least small batch.

      Thanks for the rennet post. In all of my readings, I’d never seen that it was actually “calves.” Now maybe I re-think this a little more. There’s an acceptable amount of risk in eating high quality cheese to my red meat-free diet, and I’ve recognized that for a long time.

      If you’d like to then tackle the rumor of the legally allowed amount of cow blood in milk, that would be appreciated as well.

      As for red meat and baby things… Should the time come that this is all there is in the world, I’m sure they will have had as healthy as a life as myself when I have to kill it myself.

      • Sarahwinks

        I know of a number of “local farms” who use a mobile slaughtering service where a white truck comes to the humane farm and does it onsite. Some farmers do it them selves too…….

    • seemichellecook.com

      Not really sure where you’re going with this but trading in your Humvee for an SUV is still an improvement and if everyone just made one little change then isn’t that a good thing? How can you possibly find a way to criticise someone who makes their own personal distinctions? That’s why it’s called personal.

  • Lisa

    I was never a huge cheese lover, even when it came to my pasta. I broke the cardinal rule of Italian eating by refusing parmegiano for my pasta… thankfully this was after my grandma died, or I would have met the end of a wooden spoon, haha.

    Brie’s all right, but it’s so fatty that I haven’t eaten it for years. I like a bit of organic cheddar sprinkled in a wrap every now and then for something different and do make sure it’s rennet free.

    • Aquaria

      You’re obviously profoundly ignorant of Italian pasta traditions. Parmegiano on pasta is an American thing, nitwit.

      • Elle Squared

        I love you, belated troll. I’m Canadian and don’t give a shit about American traditions.

      • Luciana

        Hey there, have you ever considered taking anger management classes? Chill dude.

        You’re completely wrong about Italy and parmigiano. I spend every summer in Italy, and restaurants and friends always offer grated parmigiano for pasta. Assicuratevi di hai raiggione prima di aprire la boca. Who’s a nitwit?

  • Guest

    I’ve just unsubbed from your facebook page. The way fooducate has decided to present rennet as something that should be avoided-when it (along with acid produced by bacteria naturally found in the milk) are the top two most natural ways milk curdles, in order to form cheese. There is nothing wrong with it, unless people want to avoid everything animal-and if that’s the case, then maybe they could look into vegan cheeses (yes, they do exist).

    • http://www.fooducate.com/blog Fooducate

      Actually, this post (unlike many others we’ve done) did not present any opinion. Just answered a question and stated facts.
      Sorry to see you leave.

    • http://ithinkitneedsmoreturbinado.blogspot.com/ SL

      I try to be vegan and I didn’t feel Fooducate was on the same page on me with this one. It didn’t convey “avoid cheese” to me.

  • Bokumad12

    To Guest who unsubbed from fooducate: The question regarding this subject matter was asked by a fooducate member. All fooducate did was answer the question!!

  • http://bakerymanis.wordpress.com andreadevon

    Tillamook and Rumiano are both national brands that do not use animal rennet in their cheese (with the exception of the white chedder tillamook, old fashioned or something). These cheeses are good quality and flavorful, so if you choose to eat cheese you can do so without rennet. It is also possible to purchase vegetable rennet and make your own cheese, should you be interested in a more radical approach! aloha from maui!

  • http://profiles.google.com/clbrns Corey Colburn

    Thanks for answering this question. I have researched and knew most of it…but it is great to have all these details in one place.

    Another subject you could follow up with: clarifying just what kosher means, and all the different symbols that are used on packaging to denote a food as kosher.

    Thanks — always informative and thought-provoking.

  • clc7

    Thanks for answering this question. I have researched and knew most of it…but it is great to have all these details in one place.

    Another subject you could follow up with: clarifying just what kosher means, and all the different symbols that are used on packaging to denote a food as kosher.

    Thanks — always informative and thought-provoking.

    • clc7

      oops…a quick search of your site shows you’ve informed about kosher before — thanks!

  • http://profiles.google.com/dm.lilith Elizabeth Courts

    Tillamook Cheese does a great job at labeling the source of their rennet. Last time I checked, they used vegetarian-friendly rennet on their cheddar (not sure about the rest of the cheeses). Check the labeling!

    • Ch33ky1

      yes, just checked a package I just bought. On the ingredients it states that no animal rennet is used. Love Tillamook!

  • http://hcgbiggirlnot.wordpress.com/ Chava

    kosher cheese will not have any meat ingredients in it, so just buy that

  • I Like Lichen

    Any ideas on how people discovered rennet. Also, why is it from a calf rather than an adult cow?

    • http://www.canadianfoodiegirl.com Andrea T

      I read the answer to this recently. My memory is slightly hazy on this, but basically it was guy wandering the dessert, had milked a cow (or goat?) in the morning and stored the milk in a wineskin made from a goat’s stomach. When he went to drink the milk he discovered cheese. It sounds like an urban legend but I read it in a book about raising goats for cheese-making.

    • Emily

      Unweaned calves have the enzymes, adult cows do not.

  • http://www.culturezest.org/home/users/detail/?UserHexID=73427218-9BE9-4919-8842-F2D519B90147 Morgan

    I had no idea that’s what rennet was. I greatly appreciate the tips for identifying and avoiding cheese made with animal rennet, as I have a friend who also refuses to eat baby animals, and this ought to help her immensely.

  • Candice

    Yeah, this is thw reason Im learning to make cheese at home! I made queso fresco last month. All it is is Milk, salt and vinegar, that’s it! No preservatives and “other” ingredients to worry about. I have the recipe on my blog:


  • Ann G

    Careful about the assumption that kosher cheese is free of renet. I researched this a few years ago for a vegetarian kid at a Jewish summer camp. Apparenly a few animal enzymes are forgivable as long as they’re super kosher. http://www.kashrut.com/articles/cheese/

  • vashini

    this really not believable,but it’s true
    i’m a vegetarian i ate cheese a lot more many times.and i just love it it when it is eaten with bread.

  • kj burnett

    The word “Kosher” does not always mean it is from non-meat sources, even when applied to dairy products. Once I called Dannon to find out if the Kosher gelatin in their yogurt was from animal sources. Dannon told me the Kosher gelatin they use is derived from cow leather.

  • Daisy

    You should read this article before you completely endorse #10: http://www.kosherquest.org/book.php?id=CHEESE.htm

  • Jon

    I am allergic to animal rennet. So you think its difficult to avoid it, can you imagine not being able to breathe if you ate it? I have a website where I list all of the cheeses in restaurants and stores that don’t contain animal rennet. http://www.safecheese.com

  • Shariq

    How can I make rennet at home if it is not easily available in the market?

    • Aquaria

      You kinda have to kill the cow and gut it to get to the fourth stomach, and then strip the lining from the inside, and then process it to get good rennet.

      Oh, you meant vegetable rennet? Well, I hope you have access to a good biochem lab. You’re gonna need it to separate, filter and purify the phytic acid from your vegetable source.

      You can buy vegetable rennet online or in some of the veg*n stores.

  • Madam

    Just buy soy cheese or other types of vegetarian cheeses. I refuse to buy cheese containing animal rennet. It’s bad enough that the male calves are ripped away from their mothers, so we can have that milk instead. The way humans use and exploit animals is disgusting. I notice several brands of cheese state “animal rennet” in their ingredients making it easier on the consumer to decide. Humans are the vilest species on Earth. We do not need dairy products in our lives to survive, so the cruelty and exploitation we put on animals is inexcusable. I hate people who are too ignorant to care.

  • JulsDiane

    Number 5 is not correct; ask Sargento and Kraft~ all of their cheese, except cream cheese, and all commercial cheeses used in restaurants are made with animal enzymes. Animal rennet is no cheaper than vegetable rennet.

  • Cher Stewart

    Look for “vegetarian” cheese as well. Tilamook’s are great!

  • Jess

    If you don’t like your eating to contribute to the suffering of baby animals (particularly calves), you should really give up dairy all together. The dairy industry is responsible for the deaths of countless of calves every year. Cows must give birth to produce milk. So they are impregnated, and their baby is torn from them straight after birth.
    It’s a very cruel industry.
    The good news is, there are lots of yummy, cruelty free alternatives these days! Go vegan -you won’t regret it! :D

    • Aquaria

      You’re amazingly stupid. A cow will lactate as long as she is suckled, moron. She doesn’t have to keep giving birth, moron.

      • WNCmountaingirl

        Actually it is true … a simple search and you find this info…
        A cow produces the most milk around 40 to 60 days after she’s given birth. She’s then impregnated again, after which her milk production will slowly decline, until she’s “dried off” and stops producing at about 305 days after calving. About a month later she will give birth again and a new cycle will begin.

    • Devil’s advocate

      Those mass-murderig cows! Killing millions of insects when they munch on grass! The only solution for a nonviolent future is to eradicate all life from the face of the earth, because life will always consume life. If you truly believe reducing unnecessary suffering for lower life forms, you should have compassion for the billions of microbes that you murder daily in the act of human metabolism, and kindly murder yourself.
      (Both sides of the debate should consider the middle way of permaculture raising methods and compassionate killing with ether, and also the value of alternative protein sources like insects. Going pure vegan is possible but is usually a science experiment requiring many exotic ingredients to fulfill certain nutritional requirements, whereas by eating insects one can thrive almost anywhere, like St.John the Baptist who survived on locusts and mead.

  • HazFL

    Thousands of bull calves are killed every week shortly after birth because they are of no use to the dairy industry. I don’t think that it is pleasant by any means to farm baby animals for meat, but if you use any dairy products whatsoever you are contributing to the fact that baby animals will be killed anyway. Because of the stigma behind eating baby animals there is not a sufficient veal market here (UK) for these animals to have any value to farmers and so the meat is completely wasted and discarded in most cases. If they are going to be killed anyway for this reason then I personally think it would be better if someone eats them than they be discarded. I would be surprised if rennet is not sourced from these animals prior to the meat being wasted.

  • permata

    furniture product http://permatamebel.com/

  • Truth

    Meat is meat it does not come without killing. You kill baby or young, both looses life. So unless you are pure vegetarian stop this crap. You have no right to say anything. Is white meat falls from sky? Have you seen flipping head of a chicken or struggling fish to survive? If not you should how gross your thoughts are.

  • Anonymous

    Why does it even matter if it’s from a baby animal or an adult animal as long as it’s done humanely? Yes, baby animals are cute and sweet, but a life is a life. The adult animal on the farm is no less “innocent” than the newborn animal, and it’s not like you’re not going to deprive the adult animal of a long life ahead of it when you eat meat in general.