The excerpt below is from Wrightfood blog... One of many I use as a reference.... After years of reading up on this stuff, and determining the author is reputable, I have averaged their parameters to "within" acceptable limits for a quality product... If you are using cure#2 in your products, the temperature needs to be at least 50F...
These conditions are temperature, humidity, and air flow.
In order to make a decent (and safe) product you need some way of controlling all three – or at least keeping them within a certain range. Lets look at each element separately, and see what we can do to control it.
temperature: a safe temperature range for curing meat is below 60F. Above that and bacteria grows a lot faster. Ideally you want the temperature between 50F and 60F. Below 50F and the curing process slows down a great deal, making the process take much, much longer (which also means it takes much much longer for your charcuterie to reach a safe water content level, but that is getting a bit geeky). Most likely you are going to find that you will have to cool and area to get it to 60F rather than heat it.
humidity: for most of the curing you want the humidity between 70% and 75%. Below 70% and you run the risk of the outside of your salami/meat drying out too fast, which means moisture is trapped on the inside, leading to spoilage. If the humidity is really high for too long then the sausage wont dry correctly, and you run the risk of getting a lot of bad mold on the charcuterie.
Ideally when you first put something in to dry cure, you want the humidity at around 85%, and then over the course of the next week you want to drop the humidity down to 75%. The reasoning here is that you want your humidity just a bit less than the water content of the meat you are curing – this stops the meat drying out too fast and developing case hardening. At the start of curing the meat has a lot of moisture in it (especially leaner cuts), so you want your curing humidity to almost match that. As the meat looses water you drop the humidity down accordingly (or roughly anyhow).
Typically we find that most areas in a house aren’t this humid, unless you have a cold, dank basement. Often enough we find ourselves having to add extra humidity to a space to make it perfect.
air flow: some air flow is critical in not only helping to dry the meat (pulling moisture away from the surface of the sausage), but it also really helps keep bad mold (green, black and fury mold) off the meat too – since there isn’t stagnant damp air constantly around the sausage. In practical terms this can just mean fanning the meat a couple of times a day, or setting up a low powered fan to blow a little air around.