Sulphur in whisky... how does it taste, smell

On the nose, these are the common descriptors in the extreme cases: sewage, rotten egg, acrid, pungent.

On the palate, these are the common adjectives used: burnt rubber, butyl, rubbery

Usually affects Spanish sherry matured whisky as there is some regulation in regard to the sale of used sherry barrels. I would imagine some wine cask matured whisky will be similarly affected too.

I have never encountered this in a whisky. Lucky me!

Not everyone can smell or taste sulfur in whisky, and some who do actually son't mind it.

When a sherry cask has been over-treated with sulfur candles I think those of us who can sense it would notice an off-smell and taste. I wonder if it's the vegetal notes I taste in my Bladnoch 12. On the other hand, there are naturally occurring sulfur compounds in vegetable matter (i.e. - peat) that can impart a positive note on the final product, like in HP 12.

I tried a Tomatin 18 yr and it had on the finish a disgusting taste that I can only describe as "rubber pong".