Which is correct Caster Sugar or Castor Sugar?Both are right. The spelling castor sugar used to be the prevailing one, but caster sugar seems to be more usual now perhaps because it is used by some sugar manufacturers on their packaging.Complementary Links:• Fayre, Fair and Fare : Which Is Which?• Are spellings like privatize and organize Americanisms?• Can CANNOT also be written as two words CAN NOT?• How do you spell Poppadom?• Is there an apostrophe in the Plural of Pizza? • E Words : What is the correct way to spell them? • When is it correct to use a Hyphen?• Why is YE used instead of THE in Antique English? • What is the difference between Affect and Effect? • Why is the letter F used instead of S in Old-Fashioned Spellings?• Which is correct Caster Sugar or Castor Sugar?• What is the difference between Learnt and Learned?• Why can't I find the word PERJORATIVE in my dictionary?