I often use invert sugar as a humectant in confections. The problem is that it always crystallizes after a few days.
My recipe is fairly simple.
- 1 kg refined sugar
- 200 ml filtered water
- 1 g cream of tartar
Bring to boil at 110C. Let cool.
The syrup is definitely inverted, as the taste is distinct. The invert sugar is also completely transparent which tells me there are no obvious undissolved sugar crystals.
Crystallization typically begins slowly at the point where I insert a spoon to portion out the syrup for recipes.
I store the syrup at room temperature in a glass syrup jar. I have had no luck boiling the jar in water to liquify the syrup, as it appears saturated and it returns to the crystallized state. Also I suspect the boiling temperature is above 100C, which the waterbath cannot exceed.