Is rennet Halal?

Rennet is the enzyme that curdles milk so it can become cheese. Animal rennet comes from the stomach of young calves; microbial rennet is made by microorganisms, with no animal involved. Helal Scan treats rennet as Halal unless it comes from pork, and says so when the pack leaves the source open.

Last reviewed 11 October 2026

Is rennet Halal?

Short answer

In Helal Scan, yes, unless it comes from pork. Rennet from microbes, plants or a lawful animal such as a calf is treated as Halal. When the pack does not name the animal, the app shows the result with a note. Pork rennet is not Halal. The app follows the Hanafi position here; the other schools view animal rennet from an animal not slaughtered the Islamic way differently (see below).

What is rennet?

Rennet is an enzyme mixture that curdles milk: it splits the milk protein so that the milk separates into solid curd and liquid whey. The curd becomes cheese. Its main active enzyme is called chymosin.

Traditionally, rennet is taken from the fourth stomach of young ruminants that still drink milk, mostly calves. Today rennet is also made with microorganisms.

Animal, microbial and vegetarian rennet

How labels name rennet, and what the app shows

Helal Scan reads the ingredient list and places each wording like this:

The note does not change the result. Tapping it in the app shows how the schools see it (below). The app checks every other ingredient on its own terms: if a cheese also contains gelatine, the gelatine decides.

For cheese and skyr whose list names no rennet, a vegetarian or vegan mark answers the rennet question and no note appears. A vegetarian mark next to declared animal rennet contradicts the pack, so the app does not let that mark clear anything else on the list; the rennet itself is read as above.

What the schools say

On rennet the schools genuinely differ. The app's scholar overview lists them like this:

Helal Scan follows the position of Abu Hanifa on rennet. When you tap the note, the app shows: "Permissible according to Abu Hanifa (Hanafi school). The Maliki and Shafi'i schools, and one of two views in the Hanbali school, do not permit rennet from an animal not slaughtered the Islamic way. Rennet from pork is not permissible in any school." If you follow another school, look for microbial rennet or ask the maker.

Which cheeses are made with rennet?

Most semi-hard and hard cheeses are set with rennet, such as Gouda, Edam, Emmentaler, Bergkäse, Cheddar and Parmesan, and so is mozzarella. The ingredient list does not always name the rennet. So Helal Scan also shows the open-source note on a cheese whose list names no rennet. The app treats skyr like cheese.

For Parmigiano Reggiano and Grana Padano, the protected-origin rules require calf rennet. When the pack names the calf, the app shows the lawful-animal note; when it only says "rennet", the open-source note.

Cream cheese (Frischkäse), quark and cheesecake carry no rennet note: cream cheese and quark are set mainly with cultures and acid. If the pack still names rennet, as in "Frischkäse (Milch, Lab)", the note appears as for any other cheese.

And whey?

Whey and sweet whey powder are by-products of cheese making, so the rennet question comes with them. Helal Scan treats whey as Halal: it is a milk by-product, and a whey entry on a list cannot name the rennet behind it. Where pork or rennet is declared on the list, the rules above apply.

Common questions

What is animal rennet?

An enzyme from the stomach of young ruminants, mostly calves, that curdles milk for cheese making. German packs call it Kälberlab, Kalbslab or tierisches Lab.

Is animal rennet Halal?

In Helal Scan, yes, as long as it does not come from pork. The app follows the Hanafi position and shows a note when the pack does not name the animal. The Maliki and Shafi'i schools, and one of two Hanbali views, do not permit rennet from an animal not slaughtered the Islamic way.

Is microbial rennet Halal?

Yes. Microbial rennet contains nothing from an animal, and Halal certifiers accept it. The app shows no note for it.

What does the app do with Labaustauschstoff?

It reads it like microbial rennet and shows no note. If the list says pork next to it, the product is not Halal.

Is cheese Halal when the list names no rennet?

Semi-hard and hard cheese is usually made with rennet even when the list does not say so. If nothing else on the list is flagged, Helal Scan shows such a cheese as Halal with the note that the rennet source is open. Cream cheese and quark do not get this note.

Keep reading

Please note: this page explains how Helal Scan treats an ingredient. It is not a religious ruling. For anything that matters, verify with the manufacturer and a qualified authority.