Sultanas are made from seedless white grapes. They are distinguishable by their light color compared to Raisins which appear to be darker. In South Africa you are fortunate to have a very distinguishable brand of Sultanas made by South African Dried Fruit (S.A.D) which is called Golden Sultanas, these have a very light color. Sultana's in the USA are called Golden Raisins or Thompson Seedless but appear much darker than the South African version so its not easy to distinguish between Sultanas and Raisins unless you read the label on the packaging. Sultanas are made by drying white grapes in the sun but they retain their light color as a result of the use of sulphur dioxide which also acts as a preservative. Currents are mostly used in combination with Sultanas and currants to make Christmas Pudding, Christmas Cake or Hot Cross Buns.
Raisins
Raisins are also made from dried white grapes and not red grapes. Raisins are produced by sun drying white grapes or sometimes hydrating them. The process differs depending on the brand of Raisins you buy. Raisins are best used in sweet treats like Chelsea Buns, Fruit Loaf or Scones.
Currants