The temperature during fermentation does not affect the extent of pH drop. However, it does indeed, affect the speed of the reaction of the culture with the glycogen (sugar in meat) and any added sugar. The pH drop is wholly dependent upon (a.) the type of sugar, and (b.) the amount of sugar. Although there are no strict rules governing fermentation temperature regarding time and relative humidity, there is a calculated table developed by someone a heck of a lot smarter than I am. And he probably doesn`t fall off his horse into the cacti either! Anyway, ol pard, it is called the "Degree-Hours Constant Temperature Fermentation Table". There is a copy of the table in Stan Marianski`s book, "The Art Of Making Fermented Sausages" on page 109. Stan points out that the table indicates the maximum amount of time (in hours) in which a product may be fermented, at a given "constant" temperature to drop the product to pH 5.3. Simple math is required to calculate the actual number of hours needed for any given temperature.
Ok, now figure this one out. Let`s say that Dave Zac inadvertently adds too much sugar to his favorite "fast" pepperoni recipe. What will happen? The pediococcus pentosaceus, or pediococcus acidilactici will have a feast and make one heck of a sour sausage unless Dave uses his head. Let`s say that Dave has fermented the sausage for 50 hours at 75°F. (24°C.), then suddenly realizes that he initially added too much sugar to the recipe. His recipe specifies 75 hours of fermenting. He`s already had the pepperoni in the fermentation chamber for 50 hours. What should he do?
a. give up and throw out the sausage?
b. move to another state because he`s embarrassed?
c. add water vapor to the chamber?
d. lower the temperature of the fermenting chamber?
e. slice open the sausage and rinse it out?
f. curse Chuckwagon for bringing the subject up in the first place?
The answer is (d), lower the temperature of the fermenting chamber. Why? If the 75° temperature continues, the pediococci will continue to drop the pH, even though it has already possibly reached the target drop of pH 5.3. You must understand that fermentation will continue until the lactobacilli exhausts the sugar supply or the moisture dries sufficiently to stop the bacterial growth at less than (<) 0.95 UNLESS we discontinue the fermentation. How do you do that? By dropping the temperature of course... to a point where pediococcus pentosaceus, or pediococcus acidilactici no longer thrive.
What about the remaining sugar in the sausage? Well, it contributes to the color and the flavor of the sausage by somewhat offsetting the acidic "tang". Pretty neat eh? Oh, by the way - this does not work with glucono delta lactone (Gdl) and will only slow down the fermentation. This is just one more good reason not to use another added chemical. Gdl is used by commercial suppliers to drop the pH quickly in order to pass FSIS requirements then to get their product onto the grocer`s shelves as soon as possible. They don`t care about quality and flavor... they care about profit!
Because there is insufficient time for the flavor-forming staphylococcus and micrococcus to work in "fast-fermented" sausages, these quickly fermented products will always generate a sour or "tangy" flavor. Oh yes, I almost forgot to tell you something. I noticed that during our "Project A", no one brought up the subject of smoking the salami rather than creating mold. It should be noted that smoking is never done during fermentation as it restrains beneficial bacteria. If smoked flavor is desired in a fermented sausage, cold smoke may be applied but only following the fermentation period.
Dave, you wrote:
Exactly, my friend! Fermentation is actually, "spoiling meat on purpose", BUT... using knowledge and understanding to CONTROL the process and make it safe.Heat PLUS carbohydrates PLUS humidity must all be a part of the proper recipe...true?