🧀 Istarski ovčji sir

Istarski ovčji sir / Istrski ovčji sir is a hard, full-fat cheese made by coagulating raw or pasteurised sheep's milk with rennet. ³ It is a joint PDO of Croatia and Slovenia, registered in December 2025, and it comes from sheep grazing the rocky Istrian peninsula and islands such as Cres and Lošinj. ²³

The milk comes from sheep of any breed reared exclusively in the production area. It must be processed within 48 hours of milking and cooled to at most 6 °C within 2 hours. The sheep graze pastures; concentrated feed may make up at most 20% of the daily ration in dry matter, up to 40% of the ration may come from outside the area, and ensilaged fodder is forbidden. Salt and rennet are used; lysozyme and starter cultures may also be used. ³

The cheese is cylindrical, 16-22 cm in diameter and 6-9 cm high, weighing 1.8-4.5 kg. It may be sold after at least 60 days of ripening but no later than 12 months, with at least 60% dry matter and at least 45% fat in dry matter. The rind is smooth, yellow-brown to brown, and may be protected with a colourless polymer coating. The texture is slightly elastic but sliceable to slightly crumbly; the paste is ivory to straw-coloured, generally closed, with possible evenly distributed irregular openings up to 4 mm. The flavour is full, salty and spicy, with a pronounced note of sheep's milk. ³

All stages of production take place in the defined area on the Istrian peninsula in Croatia and Slovenia, which also includes islands such as Cres and Lošinj; portioning, grating and packaging must also be done there, by the producers. The name must be shown in letters larger than any other inscription, together with the common symbol. The inscription '100 % milk from Istriana sheep' (Croatian '100 % mlijeko istarske ovce', Slovenian '100 % mleko istrske pramenke') is allowed only where the milk comes exclusively from the native Istriana breed. ³

Why sheep and not cows. Istrian cattle were kept almost only for work in the fields and were rarely milked, and what little milk they gave was drunk at home. So farmers kept sheep for cheese, and over time selected a native breed that gives the most milk: Istarska ovca in Croatian, Istrska pramenka in Slovenian. It copes well with rough karst and open-air life and can walk long distances over stony pasture, feeding on dry, old grass. One study of Istrian pasture counted 100 plant types. ⁴

Sheep on the move. For centuries flocks spent summer on hill pastures and winter near the coast. Until the 1960s some were still driven to mild areas near Poreč, Piran, Umag and Trieste, traditionally from 29 September to 24 April. Sheep's milk keeps only briefly, and summers here are hot and dry, so a hard cheese became the practical way to store its fat and protein. ⁴

Why it keeps without a fridge. Once salt in the cheese's water exceeds 5 %, about 2 % of the cheese, souring stops, so it does not spoil easily even at up to 19 °C. That suited konobas, thick-walled stone rooms that held a steady temperature. Ripening in that warmth also breaks proteins down faster, which creates the aroma compounds. Women usually made it, judging the moment to take the pot off the fire by the feel of the milk on their hands. ⁴

From feudal dues to protected name. Medieval records list it as a payment from subjects to lords, as wages in kind and even as war booty. The tradition survived war, depopulation and falling sheep numbers, and since the later 20th century it has become a symbol of Istrian tourism. Breeders' associations in both countries applied together, and the name was entered in the EU register in December 2025. ²⁴⁵

Why it matters to you. Look for the name and EU symbol; "100 %" on the label means milk only from the native breed, since other breeds are allowed. The milk can be raw or pasteurised, so ask if that matters. It may contain lysozyme, an egg-white protein, so people with egg allergy should check. Longer ageing makes it stronger, and aged cheese melts in the mouth. Cutting and packing are done by the producers in the area, because the casein mark that proves origin is destroyed when it is cut. ³