My pH is in the rise

[NCPaul]

I agree with your decision to toss this batch. With regards to temperatures and humidity, like for most things salami, it depends. For me, I’m always on high alert when I have temperatures over 40 F and enter the so-called danger zone of meat handling. When I first started learning about salami I was more than a little put off by the temperatures that were used for fermentation and then a long drying period. The danger zone is basically temperatures at which bacteria can multiply explosively (logarithmically). We use this to our advantage during the fermentation phase with the good bacteria we added as a culture. Once the pH drops below 5.3 there is sufficient acidity to create a safety hurdle for many bacteria; it is not necessary to get down to 4.9, though a recipe may end up there. More importantly, there are time limits for every fermentation temperature. The higher the temperature the shorter the time; at 80 F the limit to reach pH 5.3 is about 3 days IIRC. The humidity during the fermentation phase is kept very high (90 %) because we want the bacteria to thrive and multiply not die in a desert; later on we make them die of thirst.

In the drying phase of salami making there are several things to consider. To reach a water activity level of 0.89 we need to lose at least 30 % weight for most salamis, higher is better up to about 40 % (really hard to cut and chew). The starting salami has about 80 % water in it and the water wants to evaporate. We do two things to slow this process down, we decrease the temperature and we hold the relative humidity high. We are trying to balance the rate at which water moves inside the salami with the rate at which it leaves. We are trying to hold water in by pushing on it with high humidity. After the salami has lost a lot of its water weight, we can gradually lower the relative humidity. The larger the diameter of the salami, the longer it takes for water to move inside (the length doesn’t matter). A finely ground salami will lose weight slower than a coarsely ground one. So within the ranges of temperatures and humidifies we might want to start cool and wet for a large finely ground salami where we want slow even drying then move to lower humidity later on. As an extreme example of thin salami would be fermented snack sticks in lamb casings (18-22mm) which can be dried in two weeks’ time with the low humidity found in home refrigerators.

Here are some good threads to read:

viewtopic.php?f=6&t=12504
viewtopic.php?f=1&t=12580
http://www.localfoodheroes.co.uk/?e=529