Casu Marzu: the cheese of Sardinian pastoral tradition

👉 (Cover image: Casu Marzu — Photo: Shardan / Wikimedia Commons — Licence: CC BY-SA 2.5 https://creativecommons.org/licenses/by-sa/2.5/deed.it. File: https://commons.wikimedia.org/wiki/File:Casu_Marzu_cheese.jpg. No changes to the image.)

A cheese that divides opinion, intrigues and tells the story of ancient Sardinia. Casu Marzu, also known as Casu frazigu, is one of the most unique expressions of the island’s cheese-making culture.

Famous for the presence of cheese fly larvae, this creamy pecorino cheese has a history rooted in sheep farming, traditional knowledge passed down through the generations, and the relationship between people and the land.

A tradition that today also raises important issues regarding food safety.

✅ What is Casu Marzu?

Casu Marzu is a traditional Sardinian cheese made from sheep’s milk, in which the larvae of the cheese fly develop (Piophila casei).

As the cheese matures, the activity of the larvae alters the texture of the cheese, gradually making it soft and creamy.

The result is a cheese with an intense aroma and a particularly strong, tangy flavour.

Depending on the area of Sardinia, it is also known as Casu frazigu, Casu becciu, Casu fattittu or Hasu muhidu: names which bear witness to the widespread nature of this tradition across the region.

✅ A tradition from rural Sardinia

To understand Casu Marzu, one must look at the history of Sardinian sheep farming.

For generations, cheese-making has represented not only an economic activity, but also a wealth of knowledge, practices and family traditions.

Casu Marzu is part of this cultural world.

What makes it special lies not only in the maturing process, but also in the stories, customs and knowledge associated with the pastoral world.

It is a testament to the material culture that helps to define the identity of Sardinia’s rural communities.

✅ Recognition as a traditional product

Casu Marzu, known as Casu frazigu, features on Sardinia’s list of Traditional Agri-Food Products (Prodotti Agroalimentari Tradizionali - PAT).

This accreditation attests to a long-established production tradition, in accordance with the criteria set out in national legislation.

👉 However, inclusion on the PAT list does not constitute authorisation for unrestricted marketing.

Cheese, in its traditional form containing maggots, does in fact raise concerns regarding the health and hygiene standards applicable to foodstuffs intended for the market.

✅ Is Casu Marzu legal?

It is one of the most frequently asked questions.

The answer requires a distinction to be made: recognition of a cultural and culinary tradition does not amount to authorisation to sell or serve the product.

The sale of traditional Casu Marzu is not permitted under current health and hygiene regulations, due to the risks associated with the presence of larvae.

This does not prevent us from studying its history, documenting its characteristics and explaining its cultural significance.

Casu Marzu therefore remains a controversial part of our culinary heritage, where tradition and food safety must be carefully balanced.

✅ A cultural heritage worth discovering

Beyond its international fame, Casu Marzu offers an insight into rural Sardinia and its wealth of traditional knowledge.

To tell its story means looking beyond the image of an unusual or extreme cheese, in order to understand the human and cultural context from which it originates.

Because food traditions are not just about what we eat: they also tell the story of communities, their work and their relationship with the local area.

✅ Frequently Asked Questions

What does Casu Marzu mean?

The Sardinian term literally means ‘rotten cheese’. There are several local names for it, including Casu frazigu and Casu becciu.

Why does Casu Marzu contain larvae?

This is because, during the maturing process, the cheese fly (Piophila casei) becomes involved, and its larvae alter the texture and characteristics of the cheese.

Is Casu Marzu a PAT product?

Yes. It is recognised as one of Sardinia’s Traditional Agri-Food Products (Prodotti Agroalimentari Tradizionali - PAT) under the name ‘Casu frazigu.

Is it possible to buy or taste it legally?

PAT certification does not authorise the sale of the traditional product containing larvae. Food safety regulations prevent its normal marketing and require specific checks to be carried out for any initiative involving its consumption.

✅ For further reading

• Autonomous Region of Sardinia — List of Traditional Agri-Food Products.
• Autonomous Region of Sardinia — Factsheet on Casu frazigu.
• Slow Food Foundation — Casu Marzu, Ark of Taste.
• European Union — Regulation (EC) No 853/2004, specific hygiene rules for food of animal origin.

AI Disclosure

This content was produced by Antonio Casu with the support of OpenAI’s artificial intelligence tools (ChatGPT) for research, source analysis and editorial review, under the author’s supervision and responsibility.