ABCs of the Istrian Prosciutto
Definition
Istrian prosciutto-pršut is a long-life dry-cured meat product treated in the Istrian way with or without pelvic bone, dry-salted with sea salt and natural spices and then left in the open air to ripen, without being smoke-cured.
Author of the articles:
Prof. dr. sc. Romano Božac
Natural conditions in Istria
The Istrian prosciutto is produced mostly in the inland of the Istrian Peninsula where climate conditions enable dry-salting of meat and prosciutto production only during winter. Broader Pazin area is the best indicator of climate conditions characteristic for the central part of Istria. According to the figures published by the Meteorological and Hydrological Service of Croatia (DHMZ), medium temperatures and relative humidity levels common from December to March favour the optimal natural drying of meat.
Lower morning temperatures (3-4 °C) and gradual decrease of relative humidity level (65-70 %) enable regular drying and ripening process of the prosciutto. By the arrival of spring and consequently, warmer days, prosciuttos are transferred to ripen in the cellars with optimal air temperature being 13-15 °C and stable humidity level of 65-70 %.
The Istrian climate is distinguished by its winds that enable faster drying of the prosciutto. According to the Croatian Meteorological and Hydrological Service, in the period from 1989 to1998, only 11 % of the year in the central part of Istria was wind-free. The central part of Istria is characteristic for its east and southeast winds, as well as south winds.
North and northeast winds, as well as the east wind blowing from Mount Učka have been the most responsible for the appropriate drying and ripening of the prosciutto under natural conditions.
Natural conditions in Istria provide an ideal environment for the production of the Istrian prosciutto in the traditional way because, owing to the influence of the Mediterranean climate, extremely low temperatures are uncommon here and the area is frequently refreshed by winds.
Pork hogs used for the production of ham
At local homesteads prosciutto has been traditionally produced from heavy pork hogs (150-200 kg) raised for one's own needs and today, production has considerably expanded to satisfy the needs of the growing tourist industry. In the last 20-30 years, white porker breed has been raised, such as the Large White, Swedish Landrace, Dutch Landrace and their half-breeds.
The feeding of pork hogs intended for the production of Istrian prosciutto has been based on animal beet, pumpkin, potatoes, cereal crops, corn, and other plants. Hogs are often kept grazing, so their diet also contains oak acorn, various roots and subterranean habitats of various mushrooms (tubers, truffles).
Production technology of the Istrian prosciutto
The primary treatment of fresh prosciutto is unique because Istrian pršut has traditionally been treated together with pelvic bones. The hip bones remain on the fresh prosciutto i.e., the flanking bone (os ilium), as well as the ischium (os ischii) and pubic bone (os pubis), while only sacral bone (os sacrum) and caudal vertebrae (vertebrae caudales) are removed. Pig's foot is removed at the ankle joint (articulus tarsi), so that the lower leg (tibia and fibula) remains joined to the proximal row of talus (talus and calcaneus). Hide, together with fatty tissue, is removed from the outer (lateral) and from the inner (medial) side of the fresh prosciutto-ham up to the height of about 10 cm proximal from the articulus tarsi. Prosciuttos treated in this way have a characteristic extended appearance and uncovered surface.
The custom of salting and drying
Salting and dry-curing of the fresh prosciutto is typical for the countries of the Mediterranean, especially for the countries like Italy and Spain. However, German Schwarzwald and Westphalian ham, French Jambon de Bayonne, well-known Finnish Steam-Bath prosciutto and Country-style prosciutto produced in the States.
As for the Republic of Croatia, the Istrian peninsula with microclimate conditions and cultural surroundings represents an area where a unique prosciutto brand has been produced for centuries. From the old times to this day, the autochthonous prosciutto has been number one quality product in the Istrian gastronomic offer and a true pride of every Istrian.
The distinctions of the Istrian prosciutto have made it different from many other types produced all over the world. The treatment of the fresh prosciutto dates back to the period when local homesteads needed to produce larger quantities of fatty tissue which was rendered into lard and kept for future use. The treated fresh prosciutto must be dry-salted with sea salt and seasoned with natural spices, such as pepper, bay leaves, rosemary and garlic.
The drying and ripening of the prosciutto under the Istrian climate conditions lasts for 12-18 months. The product is distinguished by its specific aroma and smell, as well as by its moderately salty taste, uniform red colour and desirable consistency.
The Istrian prosciutto doesn't contain dangerous additives, as no nitrates or other unhealthy additives are used during salting. Smoke-drying is not applied in the production process of the prosciutto and thus, the final product doesn't contain dangerous carcinogens found in smoke (polycyclic aromatic compounds, tar, formaldehyde, cresols, ketones, carbon monoxide, pyridine, etc.).
With reference to the above mentioned, Istrian prosciutto is an autochthonous, top quality product and the most outstanding representative of culinary art and tourist trade in Istria.
Its authenticity has been protected by the authentic distinctive mark with the National Intellectual Heritage under No. G20020002A, published in the Croatian Intellectual Heritage Herald No. 2/2002. It was registered under a protected designation of origin in 2015 in the European Union.
Salting of the Istrian prosciutto
Production techniques applied in Istria include only salting of the fresh prosciutto. The treated prosciutto is cured with sea salt only or with a combination of sea salt and natural spices. Most frequently, a mixture of sea salt and ground black pepper (Piper nigrum) is used, as well as garlic (Allium sativum).
The mixture used for salting of the Istrian prosciutto contains 94-98.5 % NaCl, 1.5-3 % ground pepper and 1.5-2 % garlic. Immediately before salting, the left-over blood from the femoral artery is strongly squeezed out from the prosciutto (a.femoralis) and other parts containing blood. Now, salt and spice mixture is rubbed well into the fresh prosciuttos placed one above the other in 3-5 layers, with the inner (medial) side turned upwards. After seven days, these prosciuttos are rubbed again with the same mixture and placed one above the other, but this time the inner (medial) side is turned downwards.
Prosciutto laid in this way is put to rest for another 7 days and the surrounding temperature in the perfectly clean deposit room must not exceed 3-6 degrees Celsius. The pressing of the prosciutto follows within 7 days and it takes place in the same room or in some other room where the air temperature must not exceed 3-6 degrees Celsius, with the relative humidity level being 80-90 %.
Drying and ripening
Drying of the prosciutto is carried out in clean rooms only, exposed to dominant winds (draught). The air flow speed can be adjusted by opening and closing of the opposite windows, and it is desirable that the air flows at the speed of 10 cm/sec.
By the end of April when prosciuttos have lost up to 25 % of their initial weight, they are transferred to the chambers with monitored microclimate or to cellars with stable temperature and air humidity. The area must be protected from the inflow of various moths and other insects (window nets), and the optimum air temperature should be 13-15 degrees Celsius with the relative humidity level 65-70 %.
In these chambers the ripening process of prosciutto lasts for about 12-18 months with a completely gentle air rotation. The above stated microclimate conditions contribute to an appropriate ripening process with a gradual moisture loss. The appropriate air humidity level of the room where the prosciutto is left to ripen is crucial in order to prevent growth of undesirable microorganisms leaving toxic residues and unpleasant smell.
Chemical composition of the Istrian prosciutto
The chemical composition depends directly on the type of breed, feeding, the manner of keeping and pigs' health condition. On the average, Istrian prosciutto contains about 66 % of dry substance, 40 % proteins, 17 % fat, 8.5 % ash and 85 mg/100g cholesterol and 5.5-6 % salt.
Apart from that, Istrian prosciutto contains Calcium (Ca), Phosphorus (P), Magnesium (Mg), Natrium (Na), Potassium (K), Manganese (Mn), Copper (Cu), Zinc (Zn) and Iron (Fe). Furthermore, the autochthonous Istrian prosciutto contains 18 essential and semi-essential amino acids, and the total of 21 saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA).Within the intramuscular fat of the Istrian prosciutto 40.5 % accounts for the saturated fatty acids (SFA), 44.5 % accounts for the monounsaturated fatty acids (MUFA) and only 12.5 % accounts for the polyunsaturated fatty acids (PUFA).
As concerns the more significant fatty acids values, 12 % accounts for the essential acids from the Omega-6 group (arachidonic, linoleic, eicosardienoic), while 0.96 % of the total amount of polyunsaturated fatty acids (PUFA) accounts for the Omega-3 group (linolenic, eicosapentaenoic, docosapentaenoic, docosahexaenoic).
Organoleptic features
Istrian prosciutto is distinguished by very intensive fermented pork meat smell and aroma and has got a uniform red colour, moderate salty taste and favourable consistency.
During dry-salting, owing to the influence of salt and autolytic processes, the prosciutto meat starts to soften up and the procedure of ripening continues along with moderate and uniform moisture loss. Specific taste and aroma of the ripened prosciutto derive from the products of proteolysis i.e., the decomposition of proteins (polypeptides, peptides, ATP and free amino acids).
Lipolytic products have also a particular influence on the aroma, smell and taste, developing from the decomposition of fat i.e., triglycerides, phospholipids and free fatty acids, as well as products of their further decomposition. Very significant is also the fact that moderate quantities of salt and other natural seasoning used in salting, have been particularly responsible for the very specific smell and taste of the Istrian pršut.
