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Is rennet halal? Calf stomach, pig pepsin and the schools of law

The cheese guide explains which word on the pack matters. This page asks what is behind the word: what German law allows under the name rennet, why the four schools of law do not judge animal rennet alike, and what Tayyib shows for each wording.

Published 4 October 2026

Rennet is a mixture of enzymes that makes milk curdle. Its most active component is chymosin, and it usually contains pepsin as well. It is traditionally taken from the abomasum, the fourth stomach of young ruminants, that is calves, lambs or kids. Whether a cheese made with it is halal turns on two questions no pack has to answer: which animal did the enzyme come from, and how did that animal die?

What may be called rennet in Germany

Since 14 June 2026 the German Milk Products Quality Regulation (MilchPQV) has governed what cheese may be made with. It replaced the old Cheese Regulation but changed little on this point. Under its section 28, cheese makers may use:

• Rennet, or preparations of rennet, ruminant stomach pepsin or pig stomach pepsin, provided a preparation contains at least 25 per cent chymosin.
• Rennet substitutes (Labaustauschstoffe): under section 3 of the regulation, enzyme preparations on a microbial or plant basis that set the milk instead of rennet. They may also be called microbial rennet (mikrobielles Lab).

This leads to the point most lists on the subject pass over: German law permits a rennet preparation containing pepsin from a pig's stomach. How often that happens today cannot be seen from outside, and the regulation does not require it to be printed on the pack. The word rennet on its own therefore does not rule out pig. Rennet substitute and microbial rennet, on the other hand, rule out every animal, because that is exactly how the regulation defines them.

Why there is often no ingredient list at all

Article 19 of the Food Information Regulation (EU) No 1169/2011 exempts cheese from an ingredient list if nothing has been added apart from milk products, enzymes, the micro-organism cultures needed to make it and, except for fresh and processed cheese, the salt it needs. A piece of Gouda or mountain cheese may therefore be sold without a list, although it contains rennet. Many cheese makers print the list anyway. If it is missing, that is no sign of cheese without rennet, only of a pack that makes use of the exemption.

Without an ingredient list no scan can answer the rennet question, Tayyib included. Then the only way is to ask the cheese maker.

How the schools of law judge animal rennet

Three cases need to be told apart, and only one of them is disputed.

• Rennet from a permitted animal slaughtered as halal: permitted, the schools agree on that.
• Rennet or pepsin from the pig: forbidden, again unanimously. A specialist seminar of the International Islamic Fiqh Academy of the OIC, held in Jeddah in February 2015 together with the Islamic Organization for Medical Sciences, stated this explicitly.
• Rennet from a permitted animal not slaughtered Islamically: disputed, and this is exactly the normal case with European calf rennet.

There are two old answers to the third case. The Maliki and Shafi'i schools and the prevailing Hanbali view hold such rennet impure, because it comes from an animal that was not slaughtered, and the cheese made with it not permitted. Abu Hanifa and a second narration from Ahmad ibn Hanbal hold it pure: the rennet does not die with the animal, it lies in its stomach and is not part of its flesh. Ibn Taymiyya took this view and pointed out that the Companions of the Prophet ate the cheese of the Magians, the Persian Zoroastrians, whose slaughter no school regards as valid. At the same time he called it a question in which one may follow either view.

The 2015 seminar followed the majority: most participants held rennet from animals not slaughtered to be neither pure nor permitted, while some took the opposing view. So there is still no agreement on it today.

Whether a calf slaughtered by non-Muslims in a European abattoir counts as an animal slaughtered by the People of the Book is a separate dispute. It concerns all meat, not only rennet, and Tayyib does not decide it: the app reads meat from land animals without halal evidence as doubtful, and rennet from the calf's stomach likewise.

Why Tayyib says doubtful

If the list only says rennet, both questions are open: the animal and the slaughter. By the majority view calf rennet without halal slaughter would not be permitted, by Abu Hanifa's it would be pure, and the law even allows pig pepsin in the preparation. A prohibition would be an assertion without evidence, a clearance would pass over the majority of the schools and the pig question. The result is doubtful, in every madhhab setting of the app, because that setting only affects seafood.

What Tayyib shows for each word

• Lab, Labferment, Kälberlab, Naturlab, tierisches Lab on German packs, and rennet, animal rennet or calf rennet in English: doubtful.
• Pepsin with no origin and Rindermagenpepsin (cattle stomach pepsin): doubtful, for the same reason.
• Schweinepepsin, Schweinemagenpepsin (pig pepsin), "Lab (Schwein)", or porcine pepsin in English: not halal.
• Mikrobielles Lab, Labaustauschstoff, Chymosin, and microbial rennet in English: no flag.
• "mit mikrobiellem und tierischem Lab" (with microbial and animal rennet), as some cheese blends say: doubtful, because part of it is animal.

The same applies on other foreign packs: French présure and pepsine, Turkish peynir mayası. If microbienne or mikrobiyal stands with it, Tayyib flags nothing. If a word for pig stands with it, such as de porc or domuz, the app reads the ingredient as not halal.

A question that has an answer

If the pack does not name the kind of rennet, ask the cheese maker in a way that needs a concrete answer: "Which rennet do you use for this cheese, microbial rennet, fermentation-produced chymosin or animal rennet? If animal: from which animal, and does the preparation contain pepsin from the pig?" The cheese maker knows the answer, because it buys its rennet with a product data sheet.

In short

• Rennet consists mainly of chymosin and pepsin and traditionally comes from the stomach of young ruminants.
• Under section 28 MilchPQV a rennet preparation may contain pig stomach pepsin. Rennet substitute and microbial rennet, by contrast, are animal-free under section 3.
• Cheese made from milk, enzymes, cultures and salt needs no ingredient list. If the list is missing, the rennet is not.
• Rennet from the pig: forbidden. Rennet from an animal slaughtered as halal: permitted. Rennet from a calf not slaughtered Islamically: not permitted by the majority, pure according to Abu Hanifa.
• Tayyib: rennet of unnamed kind doubtful, pig pepsin not halal, microbial rennet not flagged.

Frequently asked questions

Is rennet halal?

That depends on the animal and the slaughter. Microbial rennet is unproblematic, and so is rennet from an animal slaughtered as halal. Rennet from a calf not slaughtered Islamically is held not permitted by the Malikis, the Shafi'is and most Hanbalis, and pure by Abu Hanifa. That is why Tayyib reads the word rennet on its own as doubtful.

Can rennet contain pig?

Yes. Under section 28 of the German Milk Products Quality Regulation a rennet preparation may contain pepsin from a pig's stomach, as long as it contains at least 25 per cent chymosin. This does not have to go on the pack. If pig pepsin is on the list, Tayyib reads it as not halal.

What is a rennet substitute?

An enzyme preparation on a microbial or plant basis that sets the milk instead of rennet. That is how the German Milk Products Quality Regulation defines it, and it also allows the name microbial rennet for it. No animal is involved, and Tayyib does not flag it.

Why is there no ingredient list on my cheese?

Because cheese made from milk, enzymes, cultures and salt does not need one under Article 19 of the Food Information Regulation. A missing list therefore does not mean there is no rennet in the cheese. Without a list, Tayyib cannot answer the rennet question either.

Does the Hanafi setting in the app change anything?

No. The madhhab setting only affects seafood. If you follow the Hanafi view on rennet, you can weigh the flag on calf rennet differently for yourself, but the app does not make that decision for you.

Next: is cheese halal? →

Note: this article is not a fatwa and not a certification. Tayyib shows whether an ingredient is flagged, where it typically comes from and why the origin decides it. In case of doubt, the binding assessment rests with the manufacturer or a recognised certification.