Dry cured hams are not injected with a curing solution or immersed in it. They may be smoked or not. Today, dry cured hams may be marketed as items that need preparation on the part of the consumer to make them safe to eat. As with all meat products, it is important to read the label of hams to determine the proper preparation needed. These uncooked hams are safe stored at room temperature because they contain so little water that bacteria can not grow. The way dry hams are made today is not much different from the process that was performed in the past. The difference lies mainly in climate control.
In the past this process relied on understanding the local climate and the experience of the operator. He had to decide on a daily basis which windows to open or how much water bring inside. This empirical knowledge was not acquired overnight but was passed from father to son. Today the technology of making dry products depends on the same steps as in the past, the difference is that temperature and humidity of drying chambers are computer controlled.
Since dry curing draws out moisture, it reduces ham weight by at least 18% - usually 20 to 25%; this results in a more concentrated ham flavor. Dry hams are saltier than other products and before serving are often soaked in water for 6-12 hours in refrigerator. The 5-6% or more salt they contain is added for safety reasons, to eliminate the growth of spoilage and pathogenic bacteria. This salt plays a crucial safety factor in the initial stage of the process, when the product contains a lot of moisture. As curing and drying continues, the ham loses more moisture and less water remains available to bacteria. Dry-cured hams may be aged more than a year. Six months is the traditional process but may be shortened according to aging temperature.
The manufacture of loins and shoulders is very similar to the process of making hams, the difference being the size of the product which influences the length of curing and drying.
The most popular hams:
The most popular Italian hams (prosciuttos in Italian) are: Prosciutto di Parma, Prosciutto di San Danelle, Prosciutto di Modena, Prosciutto di Carpegna, Prosciutto di Norcia, Prosciutto Toscano and Prosciutto Veneto Berico-Euganeo.
Then there is Prosciutto Cotto which is Italian cooked ham. Cooked hams are easier to produce and every country makes their own.
Without a doubt the hardest product to make at home will be European dry cured hams due to their long curing and maturing times. This will require climate controlled drying chambers and a significant time investment. Another factor which is beyond our control is the meat quality. All great Spanish and Italian hams are produced from pigs that graze freely on a pasture and their diet is supplemented by natural foods only. No chemicals or antibiotics are permitted.
The manufacture of dry products such as hams, shoulders, butts or loins generally follows these steps:
Meat selection, cutting and trimming.
Salting/Curing/Overhauling.
Resting/Equalizing.
Drying and smoking (smoking is optional).
1. Meat selection. Dry hams are usually made from whole legs. It must be remembered that pork pork should be either certified free of Trichinosis or treated according to the USDA specifications.
2. Curing. In the past when meats had to be kept without refrigeration the curing times were longer. For example the standard curing time for large pieces as ham and shoulders was about 3 days per pound and 2 days for small pieces like bacon. Even then, those curing times would be shortened by 1/3 when a product would be consumed sooner.
A mixture of salt and nitrite is applied to the surface, then more salt is added on top and the meat is left top cure. A lot of salt is added as at this initial stage, this is the only protection against the growth of spoilage and pathogenic bacteria. Keep in mind that these products are not cooked and this is why more salt is needed. Since dry curing draws out moisture, it reduces ham weight by at least 18% - usually 20 to 25%; this results in a more concentrated ham flavor.
Overhauling. In the first days of curing, the salt rapidly extracts moisture from the meat. Some of the salt is absorbed by the meat, but some salt dissolves in the newly created liquid and drains off. This resulting liquid is not needed and is removed by storing hams in containers that have holes at the bottom or laying hams on slanted tables. To continue the curing process, more mixture must be added. In addition when many meat cuts are cured together, some pieces may press against each other, preventing the cure from penetrating the meat. Overhauling which is basically re-arranging the order of cured meat, takes care of the problem.
3. Equalizing/Resting. Hams are rinsed with tap water and any residual salt is brushed off from the surface. Then they are hung or placed on the shelf for salt equalization. This step takes 1-2 months depending on the size of the ham and other factors. The humidity is decreased as the drying continues. This step resembles drying fermented sausages. Due to the accumulation of salt inside, hams are bacteriologically more stable and will become more stable due to the continuous evaporation of moisture. Salt diffuses to all areas of the product and drying continues.
Equalizing and resting hams is essential for:
Development of a proper colour.
Development of flavor. The flavor should depend on the natural flavor of the meat itself and not on adding a variety of spices. The aroma of spices will not last for six months or longer and those are the times needed to make those products. The final flavor is the result of naturally occurring reactions inside of the meat and fats as well.
4. Drying/Smoking is usually performed at 54-76° F (12-24° C) and every manufacturer has his own method, temperature range, humidity and air speed control. For products made at home, staying below 59° F (15° C) is the recommended setting as at this and higher temperatures pathogenic Staphylococcus aureus starts to grow faster.
Cold smoke (< 68° F, 20° C) can be applied during the drying process. Cold smoking is basically drying with smoke and can be applied for a few weeks for 3-5 hours every day. Smoking inhibits the growth of bacteria on the surface of the product and prevents molds from growing. It also imparts a different flavor to the product which is liked by many consumers.
The factors affecting drying ham:
Diameter of the meat.
Amount of fat or skin on the surface (ham).
Amount of intramuscular fat (ham) or fat trimmings in the sausage.
Water content of the ham or sausage.
The drying is also affected by the temperature, humidity and the air flow. Growing molds can impede evaporation of water by closing the pores on the surface. One of the methods to slow down water loss in the later stage of the drying process is to spread a thin layer of lard on ham’s surface. In a traditional meat plant producing hundreds of hams at a time, the quality control was based on visual inspection and sniffing techniques. A small probe, usually a thin horse bone 8 inches (20 cm) long and 1/8 in (3 mm) diameter was inserted into areas of the ham that are prone to spoilage. The probe was immediately sniffed by the expert to detect any unusual odor. With scientific advance in the field of instrumentation, there are electronic instruments that are able to sniff any off-odors as well.
European dry hams need almost one year to manufacture and the total weight loss in relation to the original weight is around 30 percent. The highest quality hams are usually produced with bones intact. Boneless hams, after drying, will have their bones removed by an expert and then compressed to obtain a desired shape.
Formulations From The Past
Hams
In the past the classical dry mix formula for 100 lbs of meat was:
8 lbs. salt
3 lbs. sugar (optional)
3 oz. nitrate (saltpeter)
Using recent standards for dry curing 100 lbs of meat, we can apply 453 g (1 lb.) of Cure #1 (or less) to be in compliance with the maximum allowed level of 625 ppm.
Pepper or other spices may be added to the curing mix.
This formula was applied at the rate of 1¼ to 1½ ounces per pound of meat. One ounce of mix per one pound of meat was considered the minimum amount.
Application
The dry mix was divided into 4 equal parts and 2 parts were set aside for later use.
The hams were kept at 38-40° F (3-4° C), and at high humidity to prevent excessive drying and hardening of the surface which would have inhibited moisture removal during the drying process. Hams were placed fat side down and the curing continued for about 2-3 weeks. The general curing times for hams were as follows:
2 days per pound for small pieces and the bacon.
3 days per pound for hams and shoulders.
Making Your Own Cure Mix
The allowed amount of nitrite that goes into dry products is 625 ppm. For comparison, the amount of permitted nitrite in regular comminuted products (sausages) is 156 ppm, which is four times lower. The reason is that dry products take much longer to make and nitrite dissipates in meat rapidly, especially at higher than refrigerator temperatures. Some of the mix falls off the meat during rubbing in, some mix is washed away by the draining liquid.
All you have to decide is how salty of a product you desire. Get the calculator and punch in some numbers.
Example:
How much dry cure is needed for 1 kg (2.2 lbs) of meat?
Salt at 6% = 0.06 x 1000 g = 60 g
Sugar 2% = 0.02 x 1000 g = 20 g
Cure #1 = 0.01 x 1000 g = 10 g
The percentage of salt and sugar in the above table is not set in stone. You can use less salt or more sugar, depending on what product is produced. Dry cured ham that will not be refrigerated needs 5-6%, refrigerator kept loin or bacon will need less.
Dry Cured Loins, Shoulders and Butts
The technology of making shoulder and butts follows the rules for making hams, but the process is faster due to the smaller size of meat cuts.
Salting - about 7 days, 36-40° F (2-4° C).
Equalizing - 30 days at 46° F (8° C), 75% humidity.
Drying/Maturing - 21 days, 68-72° F (20-22° C), 65-70% humidity.
When drying is performed at lower temperatures the time will be longer, for example at 54° F (12° C), 70% humidity it may take 6 weeks.
Loins are ready when about 35% weight loss has occurred.