Starter culture is a strain of bacteria with a particular characteristics which is grown under laboratory controlled conditions. When added to meat it takes over the process as it competes with other bacteria for food and water. This helps to produceproduct of constant quality and the process is more predictable with a lower failure rate.
Between 1950 – 1990 we made the best processed meats and sausages ever, as the practice of adding chemicals was not common yet. Then, as the technology advanced, most countries which joined the European Common Market, were forced to conform to new standards. Those standards, unfortunately, were very relaxed and adding water, phosphates, gums, liquid smoke, curing accelerators, color enhancers, fat replacers and so on, became common. And for commercial producersit became the necessity in order to survive.
Starter cultures were invented in 1942, but became commonly available only in last 10 years. Adding starter culture offers many benefits and should be encouraged for making dry sausages. A starter culture is added in such a small amount that its uniform distribution becomes problematic. For example T-SPX culture which is used for traditionally dried sausages, is added at 0.12 g ( 0.0042 oz) per 1 kg of meat. This comes to 1/20 of a teaspoon. The only way to measure it is by using a digital scale which is accurate to 0.01 g (0.001 oz). Starter culture should not be added to meat that would be cured in refrigerator as it might trigger unpredictable fermentation. Starter culture must be mixed with meat before stuffing.
Although adding water is not recommended for meat that will be dried, nevertheless for the purpose of better distribution you may mix culture with 1 tablespoon of water, leave it for 30 minutes (to wake up freeze-dried bacteria) and carefully pour the solution over the meat.
When using starter culture we can eliminate curing meat in refrigerator and cure it directly inside the casing. After all, it makes little difference to dry sausage where the meat is cured. It takes at least one month to produce air dried sausage, so thereis plenty of time for sodium nitrite to react with meat. Just mix meat hard enough for the sausage mass to become sticky before it is stuffed. The stuffed sausage is submitted to drying process during which some slow fermentation (due to low temperature) will take place as well, providing sugar is available to bacteria.
Starter cultures are covered in detail at: