With tail of badger, it helps brew love potions (8)

'love potions' is the definition.
(philtre can mean a love potion)

'with tail of badger it helps brew' is the wordplay.
'with' means one lot of letters goes inside another.
'tail of' says to take the final letters.
'brew' indicates anagramming the letters.
The final letter of 'badger' is 'r'.
'it'+'helps'='ithelps'
'ithelps' with letters rearranged gives 'philtes'.
'r' placed into 'philtes' is 'PHILTRES'.