Sourcing
To be on the safer side, avoid buying loose sugar from the market.
Purity test
Water Test
Dissolve a spoonful of sugar in a glass of water. If the sugar is pure, it will dissolve completely and leave the water clear.
If the sugar has been adulterated with chalk powder, the water will turn slightly white.
smell it to check for the presence of urea.
If washing powder is present, it will froth.