Ganache is an oil in water emulsion. The composition of the syrup phase then controls much of your shelf life. A ganache with just cream and chocolate will have an unsaturated syrup that will allow several yeasts, molds, and bacteria to grow in days. To extend the shelf life you need to saturate the syrup with the right sugars. Addition of one of the glucose syrups, invert syrup, sorbitol, and glycerol are common. These will reduce the water activity of the syrup below where microbes can grow, below 0.65, ideally below 0.55. These syrups (doctors) all have different effects on texture, sweetness, and flavors, so you wantto see what works for you. There are many literature sources on line with typical recipes, using these syrups.
Then you have to worry about the milk fat from the cream. This will oxidize over time and bring off flavors.
Best results are a combination of one of the syrups, and so you don't need to add to much and protect the milk fat, refrigeration or freezing.
Ganache is an oil in water emulsion. The composition of the syrup phase then controls much of your shelf life. A ganache with just cream and chocolate will have an unsaturated syrup that will allow several yeasts, molds, and bacteria to grow in days. To extend the shelf life you need to saturate the syrup with the right sugars. Addition of one of the glucose syrups, invert syrup, sorbitol, and glycerol are common. These will reduce the water activity of the syrup below where microbes can grow, below 0.65, ideally below 0.55. These syrups (doctors) all have different effects on texture, sweetness, and flavors, so you wantto see what works for you. There are many literature sources on line with typical recipes, using these syrups.
Then you have to worry about the milk fat from the cream. This will oxidize over time and bring off flavors.
Best results are a combination of one of the syrups, and so you don't need to add to much and protect the milk fat, refrigeration or freezing.