Mite- and larva-ripened cheeses

Also called Cacio marcetto, Pecorino marcetto, cace fraceche, Pecorino marcetto, Cacio marcetto (PAT, Abruzzo), marcetto, Abruzzo larva cheese.

spreadable cream-white to ochre, very piquant ewe-cheese paste, sold in jars

1. Mix milk with whey or milk starter in the vat
2. Coagulate with animal rennet, wild-artichoke flower infusion or fig latex
3. Break curd with the spino, short rest, then break to maize-grain sizeshort rest between breaks
4. Hand-fill baskets and drain on a sloping tablesome days, turned several times
5. Dry-salt
6. Expose cracked young forms to the cheese flyduring early ripening, while whey may still be present
7. Larval digestion of the pasteseveral months, over many fly generations
8. Dig out, jar and chilluntil eaten

Safety: ONAF states the larval character does not make marcetto hygienically dangerous. Sale of larva-ripened cheese conflicts with EU and Italian hygiene rules (casu marzu precedent), so it is a PAT product made under local derogations. Season May–October.

• ONAF, scheda 'Cacio marcetto – Pecorino marcetto', (PAT Regione Abruzzo)
• Il Post, 'La prelibatezza nostrana del formaggio con le larve', 2025-06-12
• Wikipedia (it/en), Casu marzu, regional variants list

Also called casu marzu, casu modde, casu cundídu, casu fràzigu, formaggio marcio, maggot cheese.

soft, pungent cheese with live larvae

1. Make pecorino; leave rind cut or openedweeks into ageing
2. Fly oviposition (or introduce larvae)days
3. Larval digestion2–3 months

Safety: EU/Italian hygiene rules bar sale; risk of intestinal myiasis claimed (larvae may survive stomach acid). Recognised as a traditional agri-food product (PAT) in Sardinia.

• Il Post, La prelibatezza nostrana del formaggio con le larve, 2025-06-12
• Scatti di Gusto, Casu marzu
• Cooksinfo, Casu marzu

Made from many base cheeses (semi-hard, cooked or pasta filata) by letting cheese-fly larvae cream the paste; seasonal because of the insect's life cycle.

Rind

Base cheese rind with holes made by the larvae or by the ager

Size

2–3 kg; usually cylindrical

1. Prepare the milk
2. Set the curd
3. Ripen

• ONAF, scheda formaggio 'Formaggio coi vermi' (id 1306)
• ONAF technical sheet PDF (not in bundle text)

Also called fromage fort, fromage fort de la Croix-Rousse, tracle (Bugey), strong cheese, fort.

Fromage fort is a home ferment of leftover or failed cheeses rather than a cheese made from milk. Old cheese is grated or crushed into a stoneware pot with alcohol, often white wine, and in the Lyon area leek broth; added liquid restarts fermentation. Kept going for weeks or months, it turns pungent and spreadable, and the pot is topped up with fresh cheese as it is eaten.

1. Grate or crush old cheese into a pot
2. Ferment the grated cheese (Ain method)8–10 days
3. Add wine, broth or milk and stir
4. Keep fermenting and top up

• Doane C.F., Lawson H.W., revised by Matheson K.J. 1928, Varieties of cheese, descriptions and analyses, USDA Bulletin 608 (Fromage Fort)
• Wikipédia (fr), Fromage fort (outline only)

Also called Milbenkäse, Mellnkäse, Mellnkase, Würchwitzer Milbenkäse, mite cheese.

Skim-milk quark seasoned with salt and caraway is shaped into small discs and laid in old wooden crates with thousands of live cheese mites, fed with rye flour. At about 15 °C and full humidity the mites gnaw and ripen the cheese for months, until it turns amber; it is eaten with the mites. Their secretions give it a lemon-like note.

Milk

Skim-milk quark, cow or goat

Ripening

Several months with live mites at about 15 °C and 100 % humidity

Flavour source

Neral, a lemon-oil compound in the mites' secretion; absent once the mites are removed

1. Season the quark and shape small discs
2. Lay the discs in crates of mites and rye flour
3. Ripen with the mites3–12 months · 15 °C

• Melnyk J.P., Smith A., Scott-Dupree C., Marcone M.F., Hill A. 2010, Identification of cheese mite species inoculated on Mimolette and Milbenkase cheese through cryogenic scanning electron microscopy, Journal of Dairy Science 93:3461–3468, doi:10.3168/jds.2009-2937
• Shimano S., Hiruta S.F., Shimizu N., Hagino W., Aoki J.I., OConnor B.M. 2022, Do 'cheese factory-specific' mites (Acari, Astigmata) exist in the cheese-ripening cabinet?, Experimental and Applied Acarology 87:49–65, doi:10.1007/s10493-022-00725-8
• Brückner A., Heethoff M. 2016, Scent of a mite, origin and chemical characterization of the lemon-like flavor of mite-ripened cheeses, Experimental and Applied Acarology 69:249–261, doi:10.1007/s10493-016-0040-7
• TU Darmstadt, press release 26 April 2016, Ökologen der TU Darmstadt entlocken Milbenkäse das Aroma-Geheimnis
• Voigt K.-P. 2019, Da krabbelts in der Kiste, Volksstimme, 23 November 2019
• dpa 2014, Dieser Käse lebt, Volksstimme, 19 February 2014

A larva cheese named for the jumping larvae of the same fly as casu marzu; not on the PAT list.

1. Prepare the milk
2. Ripen