Not dissolved:she sipped the undissolved sugar at the bottom of the cup...
In order to prevent this happening, most recipes suggest ‘washing’ the sides of the pan with a wet pastry brush to brush down any undissolved sugar; easier still is to put a lid on the pan and let steam do the trick.
Unsurprisingly, one week later the salt remained undissolved.
The nondescript passion fruit charlotte contained leaves of undissolved gelatine.