In essence, a teetotaller with a warm heart (5)
I believe the answer is:
attar
'in essence' is the definition.
'attar' can be an answer for 'essence' (thesaurus). I'm unsure of the 'in' bit.
'a teetotaller with a warm heart' is the wordplay.
'teetotaller' becomes 'tt' (abbreviation).
'with' is a charade indicator (letters next to each other).
'heart' means to look at the middle letters.
The middle letters of 'warm' are 'ar'.
'a'+'tt'+'ar'='ATTAR'
Can you help me to learn more?
(Other definitions for attar that I've seen before include "Fragrant essence usually associated with the damask rose" , "Fragrant oil from flowers" , "Send out roses" , "Rose petal oil" , "Fragrant oil obtained from roses" .)