Salt possibly a factor in judging bake-off? (8)

I believe the answer is:

tartrate

'salt' is the definition.
(I've seen this before)

I can't explain the remainder of the clue.

(Other definitions for tartrate that I've seen before include "compound?" , "salt" .)

I've seen this clue in The Independent.

Want a hint initially instead of a full solution? Install my app