Unpleasant quality of rotten steel basins (11)

I believe the answer is:

beastliness

I'm a little stuck... Click here to teach me more about this clue!

'unpleasant quality' is the definition.
'beastliness' can be an answer for 'quality' (beastliness is a kind of quality). I am not certain of the 'unpleasant' bit.

'rotten steel basins' is the wordplay.
'rotten' indicates an anagram.
'steel'+'basins'='steelbasins'
'steelbasins' with letters rearranged gives 'BEASTLINESS'.

'of' acts as a link.

Can you help me to learn more?

(Other definitions for beastliness that I've seen before include "Characteristic of copper" , "Unpleasant behaviour" .)

I've seen this clue in The Times.

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