In Bordeaux, I reject almost nothing from this sherry producer (5)
I believe the answer is:
jerez
'this sherry producer' is the definition.
The definition suggests a singular noun which matches the answer.
'in bordeaux i reject almost nothing' is the wordplay.
'in bordeaux i' becomes 'je' (I can't justify this - if you can you should give a lot more credence to this answer).
'reject' says the letters should be written in reverse.
'almost' means to remove the last letter (almost the whole word is kept).
'nothing' becomes 'zero' (synonyms).
'zero' with its last letter removed is 'zer'.
'zer' written backwards gives 'rez'.
'je'+'rez'='JEREZ'
'from' is the link.
Can you help me to learn more?
(Other definitions for jerez that I've seen before include "place to produce wine" , "City in south-west Spain, famous for sherry" , "Spanish city (J, not X)" , "The home of sherry" , "Andalusian city" .)