St-Germain is the world's first elderflower liqueur, made with hand-picked elderflower petals macerated in grape neutral spirit within 48 hours of being...
It will change colour and flavour, especially if the bottle is exposed to sunlight &/or excessive heat. As with most products, best stored in a cool dark place. While it may taste more honeyed and less floral, still OK to use - 20% alc./vol. prevents bacterial growth.
1) Not clear whether the 180 g sugar per litre is added to the infused spirit before or after it's diluted with water to bring the alcohol content down to the 20% alc/vol of the finished product. I'm trying to find the sugar content of the finished product.