I wanted to know if the soapmaker software shows how long recipes will last before it goes rancid. Does it provide expiration dates for the products? How long before bacteria forms; and if not how can I test my products for bacteria and expiration dates?
Unless your formula has a very high superfat percentage the soap should last years. It is unsaponified fats that will cause rancidity. If you use no more than a 5% to 6% superfat you will be fine.
We have had soap last 6 years or more sitting in the shop, no air conditioning, high humidity. The only thing that may occur is that some EOs can discolor, lavender is prone to this.
Due to individualized formulation, the broad and extensive range of possible combinations, no software will be able to predict or quantify the outcome of a formulation.