Made rare concoction of sugar (8)
I believe the answer is:
demerara
'sugar' is the definition.
(I know that demerara is a type of Brown sugar)
'made rare concoction' is the wordplay.
'concoction' indicates anagramming the letters.
'made'+'rare'='maderare'
'maderare' is an anagram of 'DEMERARA'.
'of' acts as a link.
(Other definitions for demerara that I've seen before include "Rum" , "That's sweet!" , "(Light-brown) sugar" , "sugar - and alcohol" , "Sweet thing" .)