Troubleshooting Guide for Fermented Meats

Slow acidification

Frozen culture allowed to thaw and subsequently held to long before dispensing into meat. 
Microorganisms exhaust nutrients in packet/can, reducing the pH resulting in a lower culture activity.
Environmental temperatures/humidities during fermentation inconsistent with recommended culture optimums.
Secondary growth in meat of contaminant microorganisms producing components that buffer pH drop.
Prolonged storage of the meat mixture at cold temperatures resulting in extended lag phase at the beginning of the fermentation cycle.
Cheese in product may contain phosphate that buffers pH drop; it also has a tendency to absorb moisture from surrounding meat.
Sausage entering the smokehouse/climate chamber colder than normal, for example by using very cold meat, which may prolong the lag phase of the starter culture.
Spice formulation adjustment that either decreases acid stimulation or inhibits the culture.
Excessive salt or cure addition that inhibit starter culture.
Culture contact directly with curing components may inactivate the starter culture.
High fat formulation that reduces the moisture content.
Large diameter product giving slower heat transfer.
Rapid moisture loss in product.
Insufficient carbohydrate source added to sausage mixture.

Fast acidification

Temperature/humidity is higher than normal.
Spice formulation adjustment that favors the culture.
Excessive water addition.
Product delayed prior to entering the smokehouse/climate chamber resulting in higher initial temperature.
Leaner product giving more moisture and lower salt-in-water.
Change of meat (from beef to pork) in recipe.
Smaller diameter product processed at high humidity.
Initial meat pH lower than normal.
Wrong combination of carbohydrate.
Too slow drying that allows longer acidification.

Inconsistent acidification

Inadequate distribution, resulting in hot and cold spots in meat mixture.
Inadequate distribution of culture, salt, cure, spices, dextrose.
Diverse initial product temperature.
Stored product and directly processed product in same climate chamber; culture activated in stored product resulting in a faster fermentation.
Products with different spice formulations, meat components, casing diameters, pH or water/fat content.
Uneven temperature/humidity in the climate or fermentation chamber.
Uneven humidity in dry room causing different drying rates.
Too low acidification temperature.

No acidification

Culture not added.
Culture inactivated by direct contact with salt, cure components, or heavily chlorinated dilution water.
Non-compliance with recommended handling temperatures after thawing of frozen culture.
Insufficient carbohydrate added to sausage mixture.
Excessive salt content.
Antibacterial agents added to meat mixture (preservatives, chemical boiler treatments via steam, antibiotics in meat).
Culture exposed to high temperature during transportation or storage.

Too low final pH

Failure to monitor acidification.
Excessive carbohydrate source.
Insufficient heat processing to retard fermentation (cooking procedure).
See also Fast fermentation.

Insufficient moisture loss

Excessive humidity.
Excessive air speed and/or too low humidity sealing surface pores giving case hardening/dry rim. No moisture migration from product.
Excessive smoke initially that coagulates surface proteins retarding moisture migration. Slow drying, too high pH.
No acidification.
Smearing (during grinding) preventing water loss.
Casing greasy due to fat melting commenced. Water outlet potential through casing greatly reduced.

Too much moisture loss

Excessive drying, too fast air velocity, too low humidity.
Too fast acidification.
Applying a too fast acidifier (wrong culture).

Souring of product, post-processing

Insufficient heat treatment to destroy microorganisms (cooking process) .
Residual carbohydrates in excess that permits secondary fermentation.
Excessive moisture and residual carbohydrates in non-cooked product.
Insufficient drying.
Temperature abuse post-packaging.

Off-flavor

Microbial contaminants either growing during fermentation or post-packaging.
Use of spoiled raw materials (meat).
Poor sanitation post-processing.
Chemical contaminant.

Discoloration/green or gray coloration.

No addition of staphylococci.
Oxidation of meat pigments via microbial contaminants, metal contaminants.
Exposure to sunlight.
High pH.
Excessive peroxide-forming bacteria.
Too low amounts of nitrate/nitrite added.
Too fast acidification.
Spoiled raw materials.
Chemical acidifier added.
Too low fermentation temperature.
Too much sorbate in the casing.
Growth of yeast on the surface.
Trace metals (unclean salts).
Grey/brown rim due to high smoking temperature.
Smearing preventing water loss giving spoiled (grey) center.
Excessive air speed and/or too low humidity, sealing surface pores giving case hardening/dry rim. No moisture migration from product giving grey center in sausage.

Mushy product

Over-working at mixer, chopper or grinder.
Excessive fat extension.
Insufficient salt level or no salt added.
Spoiled raw materials.
Proteolytic microbial contaminant.

Slimy, gassy-product

Yeast or heterofermentative lactic acid bacteria contamination in package post-processing.
Excessive moisture content.
Inadequate smoke concentration at product.

Greasing (fat melting)

Excessive heating rate (cooking process).
Excessive fermentation temperature.
Unstable meat mix, low-binding meats.
Overworking raw meat mixture.

This information is based on experiments made by Chr. Hansen GmbH using the Bactoferm (TM) starter culture. We hope that this information has succeeded in answering many of the troubleshooting questions that might arise.