Pudding -- useless -- Homer Simpson's kind of beer (4)

I believe the answer is:

duff

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'pudding' is the definition.
(duff is a kind of pudding)

I don't understand how the rest of the clue works.

(Other definitions for duff that I've seen before include "False; steamed pudding" , "Pudding - of poor quality - Homer Simpson's favourite beer" , "Homer's so-called favourite tipple" , "Dud - pud" , "Heavy boiled or steamed pudding" .)

I've seen this clue in The Guardian.

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