Starter Cultures for Making Fermented Sausages

Starter cultures ferment sausages, develop color and flavor and provide safety. The addition of any commercial culture to the sausage mix provides a safety hurdle, as those millions of freshly introduced bacteria start competing for food (moisture, oxygen, sugar, protein) with a small number residing in meat bacteria, preventing them from growing. It may be called a biological competition among bacteria. Bactoferm™ F-LC has the ability to control Listeria monocytogenes at the same time as it performs as a classic starter culture for fermented sausages.

Cultures can be classified into the following groups:

• lactic acid producing cultures (fermentation)
• color fixing and flavor forming cultures (color and flavor)
• surface coverage cultures (yeasts and molds)
• bio-protective cultures (producing bacteriocins). You may think of bacteriocins as some kind of antibiotics which kill unwanted bacteria. Some of the lactic acid cultures (Pediococcus) possess antimicrobial properties which are very effective in inhibiting not only Staph.aureus but also Salmonella, Cl.botulinum and other microorganisms, including yeasts.

The advantages of starter cultures are numerous:

• they are of known number and quality. This eliminates a lot of guessing as to whether there is enough bacteria inside meat to start fermentation or whether a strong curing color will be obtained.
• cultures are optimized for different temperature ranges that allow production of slow, medium or fast-fermented products. Traditionally produced sausages needed three (or more) months to make, starter cultures make this possible within weeks or even days.
• production of fermented sausages does not depend on "secrets" and a product of constant quality can be produced year round in any climatic zone as long as proper natural conditions or fermenting/drying chambers are available.
• they provide safety by competing for food with undesirable bacteria thus inhibiting their growth.

Although commercially grown starter cultures have been around since 1957, it is only recently that sausage equipment and supplies companies carry them in catalogs. As the hobbyist-sausage maker becomes more educated in finer aspects of the art of sausage making he will undoubtably start making more fermented sausages at home.

The most important microorganisms used in starter cultures are:

In addition to being very strong competitors for nutrients against pathogenic and spoilage bacteria, lactic acid bacteria are known to produce compounds named "bacteriocins" which can act against other microorganisms. Pediococcus acidilactici and Lactobacillus curvatus are known bacteriocins producers especially effective against the growth of Listeria monocytogenes.

Chr. Hansen starter cultures

There are many manufacturers of starter cultures that are used in Europe and in the USA and we are going to list products made by the Danish manufacturer "Chr. Hansen" as their products demonstrate superior quality and are easily obtained from American distributors of sausage making equipment and supplies. Even more the company offers wonderful technical support and we are deeply indebted to them for detailed specifications about their products.

5.3.1 Starter cultures for traditional fermented sausages

In the production of traditional style sausages, the fermentation profile must have a short lag phase in order to ensure the growth of the added starter culture at the expense of the unwanted bacteria. The acidification profile must be rather flat not going below pH 4.8-5.0 at any time. This will ensure that Staphylococci maintain their activity over a longer period of time; foremost their nitrate reductase and flavor forming activities.

5.3.2 Starter cultures for fast fermented sausages

In the production of North European and US style sausages the fermentation profile must have a very short lag phase in order to rapidly on-set fermentation and exibit a fast drop in pH to below 5.3 within 30 hours as a minimum. This ensures an efficient inhibition of unwanted bacteria and an early on-set of fast drying. Total production time is typically less than 2 weeks.

Culture name	Bacteria included	Characteristics
F-RM-52	Lactobacillus sakei, Staphylococcus carnosus	Fast cultures targeted for fermentation temperatures 22-32º C (70-90º F)
F-RM-7	Lactobacillus sakei, Staphylococcus carnosus, Staph.xylosus
F-SC-111	Lactobacillus sakei, Staphylococcus carnosus
F-1	Pediococcus pentosaceus, Staphylococcus xylosus
LP	Pediococcus pentosaceus
LL-1	Lactobacillus curvatus
CSL	Lactobacillus curvatus, Micrococcaceae spp.
LL-2	Lactobacillus curvatus
F-2	Lactobacillus farciminis, Staph.carnosus, Staph.xylosus
LHP	Pediococcus acililactici, Pediococcus pentosaceus	Extra fast cultures targeted for fermentation temperatures 26-38º C,  (80-100º F)
CSB	Pediococcus acililactici, Micrococcaceae spp.	Extra fast cultures targeted for fermentation temperatures 30-45º C, (86-115º F)
F-PA	Pediococcus acililactici
HPS	Pediococcus acililactici	Very fast cultures targeted for fermentation temperatures 32-45º C,  (90-115º F)

In the US style fast fermented sausages (35-45º C, 95-115º F, very fast pH drop, low final pH <4.8), Staphylococci are not added to the culture since they generally do not survive such fast pH lowering.

5.3.3 Starter cultures for enhancing flavor and nitrate reduction

Sausages fermented with a chemical acidifier such as Gdl or encapsulated acid instead of lactic acid bacteria generally require added Staphylococci or Micrococcaceae spp. to obtain acceptable flavor and color. Those single strain cultures are recommended in all sausage products in need of extra flavor or nitrate reductase activity. S. carnosus is more salt tolerant than S. xylosus and convey a more intense flavor in fast fermented products.

Culture name	Bacteria included	Characteristics
S-B-61	Staphylococcus carnosus	Flavor and color enhancing cultures
S-SX	Staphylococcus xylosus
CS	Micrococcaceae spp.

5.3.4 Starter cultures for surface coverage

Mold present on traditional sausages prevents mytoxin formation by wild molds. It allows for uniform drying and contributes positively towards flavor.

Culture name	Bacteria included	Characteristics
M-EK-72	Penicillium nalgiovense	White mold culture for surface treatment
M-EK-4	Penicillium nalgiovense
M-EK-6	Penicillium nalgiovense

M-EK-4 grows better at lower temperature and humidity and gives a marbled appearance. M-EK-6 is more dense and develops a more fluffy coverage. M-EK-72 gives a strong growth and high fluffy coverage when high humidity and temperature is available.

5.3.5 Starter cultures for bio-protection

Bactoferm™ F-LC is a patented culture blend capable of acidification as well as preventing growth of Listeria. The culture produces pediocin and bavaricin (kind of "antibiotics") and that keeps Listeria monocytogenes at safe levels. Low fermentation temperature (<25º C, 77º F) results in a traditional acidification profile whereas high fermentation temperature (35-45º C, 95-115º F) gives a US style product.

Culture name	Bacteria included	Characteristics
F-LC	Staphylococcus xylosus, Pediococcus acidilactici, Lactobacillus curvatus	Culture for acidification and prevention of Listeria

Meat culture with bioprotective properties for production of fermented sausages with short production type where a higher count of L.monocytogenes bacteria may be suspected. Bactoferm™ F-LC has the ability to control listeria at the same time as it performs as a classic starter culture for fermented sausages. Use dextrose as this culture ferments sugar slowly.

How to choose the correct culture

In order to choose the correct culture the following advise may be used as general guidelines:

1. What style of sausage is produced?
   • Traditional South and North European: choose cultures in paragraph 5.3.1.
   • North European fast fermented: choose cultures in paragraph 5.3.2.
   • US style: choose the extra fast and very fast cultures in paragraph 5.3.2.
2. A very short on-set of fermentation is needed
   • Choose a frozen culture instead of a freeze-dried culture.
   • Increase the amount of culture.
3. The salt-in-water percentage in the fresh mince is:
   • > 6% : avoid F-1, LP, T-SP and T-SPX.
4. The type of sugar is:
   • Glucose: all cultures will ferment.
   • Sucrose: avoid T-RM-53, T-SC-150, F-RM-52 and F-SC-111.

   These cultures contain Lactobacillus sakei, which does not ferment sugar well (see the table on page 43). This fact can be used to our advantage by adding sugars which will not be fermented, yet they will remain in the sausage contributing to a sweeter taste.

5. Nitrate is added as a color forming agent to the mince
   • Choose cultures in paragraph 5.3.1. and 5.3.2 and adjust the process correspondingly to traditional/slow fermentation.
   • Add extra Staphylococci or Micrococcaceae spp. from paragraph 5.3.1 to enhance nitrate reductase activity
6. A product with an intense flavor
   • Choose traditional technology and cultures from paragraph 5.3.1
   • Add extra Staphylococci or Micrococcaceae spp. from paragraph 5.3.3. to enhance flavor formation

Notes:

• Technical information sheets provide the recommended temperatures for fermentation, however, bacteria will also ferment at lower temperatures, just more slowly. For example, the technical information sheet for T-SPX lists temperatures as 26-38º C, optimum being 32º C. T-SPX will ferment as well at 20-24º C which is not uncommon for "European" style sausages, and 48 hours or more is not atypical.
• When freeze-dried cultures are used it is recommended to disperse them in water. Adding 25 grams of powdered culture to 200 kg (440 lbs) of meat makes uniform distribution quite challenging. That comes to about 1/2 teaspoon to 4.5 kg (10 lbs) of meat and the culture must be very uniformly dispersed otherwise defects will occur later on. For those reasons it is advisable, especially at home conditions, to mix 1/2 tsp of culture in 1/2 cup (150 ml) of distilled water and then pour it down all over the meat. Any tap water which is chlorine free will do, the problem is that different cities, or countries, sanitize water in different ways. Chlorine will kill bacteria and the process will suffer. For this reason it is recommended to use distilled water.
• Mixing freeze-dried cultures with cold water for 15-30 minutes before use allows them to "wake up" and to react with meat and sugar faster when introduced during the mixing process.
• Cultures distributed by Internet online companies are of the freeze dried type.
• Once fast-fermented starter culture or Gdl has been added to the sausage mix, the mix should be filled into casings.