It is the same thing and yes that's a preservative. I use it or crushed vitamin C in guacamole to keep it from turning brown. Fruit fresh might be the same thing also if I remember correctly.
Does it not need refrigeration? I've run into a few recipes for it and I just use boiling water (least amount possible to still dissolve sugar) and then ice cubes.
The reason for it is that if you have a cold beverage like tea and lemonade not everyone likes it sweet enough to rot your teeth. LOL and sugar does not dissolve well in cold liquid. In a restaurant my husband will use artificial sweetener as it does dissolve.
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*Off The Deep End~A very short trip for some!*