Malabar Reference - Dry & Semi-dry Sausage Technology

Dry and Semi-Dry Sausage are different products, and require different raw materials, processing and finishing techniques.

This reference page highlights some fundamental information on the ingredients and the processing requirements for each one, beginning with the fundamental differences between them.

The combination of low pH and reduced moisture contribute to the extended shelf life of the product.

In order to ensure proper fermentation starter cultures are used. There are two types of dry and semi-dry sausage producers who do not use starter cultures - those who have had product failures and those who are going to have product failures.

Due to the critical nature of dry and semi-dry sausage production, only the highest quality meat ingredients should be used.The reason for this is that the product will be held at temperatures ideal for microbial growth, even at reduced pH levels, for extended periods of time. Also, because of microbial concerns, particularly E. coli 0157:H7 and Listeria, products will need to be heat-treated. This usually has an impact on the texture of dry sausage.

Freshness is critical in the manufacturing of both dry and semi-dry sausage. Fats oxidize rapidly and long storage periods in either a fresh or a
frozen condition should be avoided as it may trigger the onset of rancidity in the finished product.

Temperature of raw materials is very critical. Better particle definitions are obtained at temperatures of -4° to -5°C. Low temperatures will reduce fat smearing during stuffing which will inhibit the moisture loss and result in inadequate or uneven drying, and may also interfere with
the microbial fermentation of the product.

In addition, temperatures above 4°C can promote“fatting out” of semi-dry sausages heated to temperatures of 60°C.

Salt, sodium nitrite, sodium erythorbate and seasonings are basic. Dextrose is added as a source of energy for the fermentation of the starter culture. Generally the higher the level of dextrose, the greater the degree of fermentation and the lower the pH.

Starter cultures are used for uniformity and to ensure that the pH drop will be rapid enough to inhibit the growth of undesirable organisms. Basically, two types of cultures are used -- the low temperature culture (those that grow best at 70° to 80°F) and high temperature cultures (those that grow best at 90° to 115°F).

Normally, the low temperature cultures are used for dry sausage and the high temperature cultures are for semi-dry products. Cultures generally are either frozen or freeze dried, and each requires special handling. Both are usually stored in a freezer, and are reconstituted in water, which should be neither heavily chlorinated, nor hot.

Some processors use chemical acidulants, such as GDL or encapsulated acidulants. These are not ideal, however, as they normally they cannot be used in sufficient quantity to get the low pH’s we expect and they tend to have a harsh flavour.

Due to very long processing times, natural spices appear to function better from the standpoint of flavour stability than extracts or oleoresins.
(See Herbs & Spices)

The choices for mixing are either a chopper or a grinder, and there are advantages and disadvantages to each one. The disadvantage of the chopper is it is difficult to produce uniform particles from one batch to another, also the chopper does not provide any opportunity for the use
of a bone removal system.

The grinder, on the other hand, will produce uniform particles, but unless temperatures are kept cold, it is easier to develop fat smearing and lack of particle definition. The grinder can, however, be fitted with a bone removal system. In order to reduce fat smearing and maintain good particle definition, it is preferable to go through a final grind before the meat is blended with the non-meat ingredients. During the grinding process, it is common to use a coarse grind for uniform distribution of fat, followed by a final grind of 1/8” for lean meats and 3/16” fatter meats.

The order of addition of non-meat ingredients is critical. Salt should be added toward the end of the mixing - contrary to normal procedures, where salt is added first for maximum protein extraction. Cure should be added first, followed by spices and the starter culture.

Temperatures must be cold. Anything above 4°C (40°F) may cause fatting out and fat smearing.Temperatures should be 25°-30°F while mixing
and 34°-36°F while stuffing.

Depending on the type of product, either natural, collagen, or cellulose casings can be used. Casings must be stuffed to the proper diameter.

Under stuffing can result in air pockets developing between the casing and the sausage as the sausage shrinks. Overstuffing can result in ruptured casings or clips’being forced off the casings as the meat expands during initial phases of the fermentation cycle.

To avoid smearing, the stuffing horns should be in good condition and of correct size to fit the casing, as per manufacturer’s recommendations.

The goal of the fermentation stage is to provide optimum conditions of temperature, humidity, and time for the lactic acid bacteria to grow.

Generally for semi-dry sausage, the fermentation temperatures would be in the range of 80°F to 110°F (27°-43°C) with a 95% relative humidity. Under these conditions, a good starter culture should achieve full fermentation in less than 24 hours.

For dry sausage, temperatures range from 75o to 80oF (24°-27°C) and may take as long as 48 hours to achieve appropriate fermentation.

Upon completion of the fermentation, the pH will be reduced and the product will become firm. Following fermentation, the product may be smoked.

The drying of the sausage is a very critical step. Moisture and air circulation must be balanced to remove moisture from the surface of the sausage at the same rate as the interior. In general, drying rates of more than 1.0% a day will result in case hardening. Drying room temperatures are normally maintained some where in the range of 60° to 65°F (15°-18°C) with a humidity of 80 to 90%.

The manufacturing procedures used in production of some fermented sausages place them at higher risk for certain food borne illnesses.

During fermenting, the product will be held at ideal temperatures for microbial growth (60°F (15°C) to 110°F (43°C)) for extended periods of time. Dry and semi-dry sausage will often be subjected to a relatively mild heat treatment (90°F (32°C) to 135°F (57°C)) after fermentation, which may not destroy some pathogenic organisms. Also most fermented sausages will be eaten without further cooking, so that any microbial growth that occurs during production will be transferred to the consumer.

One pathogen of concern is E. coli 0157:H7. This bacterium can potentially be life threatening, and is found in the intestinal tracts of cattle, and is in their feces. During slaughter, the organism can contaminate the carcass.

E. coli 0157:H7 can survive both refrigeration and freezer storage. If present, it can multiply very slowly at 44oF, and it may be present in a fermented product because it is able to survive pH 3.6-7.0 for substantial periods, unless it is destroyed in the process.

E. coli 0157:H7 can cause bloody diarrhea and severe dehydration, which can make it lethal for children or the elderly. Controlling E. coli 0157:H7 is critical in the production of dry and semi-dry sausage. Only the highest quality meat ingredients should be used, preferably from a supplier with a HACCP program in effect. In addition, separation of raw and ready-to-eat processing areas and sanitation and clean-up procedures are essential.

Currently, heating after fermentation is the only documented procedure for destroying E. coli 0157:H7. For example, summer sausage should be cooked to an internal temperature of 135°F (57°C) and held for 5 minutes minimum.

Questions? Contact our technical specialists
@ 1-888-456-6252, or at lab@malabarsuperspice.com.
We’re here to help!