If you have ever tasted a whisky and picked up a note of sulphur that, for one person evokes “delightful meaty peat” while another tastes “burnt match-sticks and rotten cabbage”? That note is sulphur and it can strike different whisky enthusiasts in remarkably different ways.
Why do barrels get sulphur in them?
In the production of barrels (especially wine or sherry casks that later become whisky barrels), burning sulphur wicks inside the empty cask is a common method of sanitising and preserving the wood. The smouldering sulphur releases sulphur dioxide (SO₂) and related compounds, suppressing microbes and oxidation in the wood. If the barrel isn’t simply re-aired or washed sufficiently before being used, traces of sulphur-related compounds can remain in the wood and thus pass into the spirit during finishing or maturation.
When sulphur compounds show in whisky
Once a whisky is being made, there are a number of critical stages where sulphur (or more precisely volatile sulphur compounds, VSCs) can enter the aroma/flavour palette:
- Fermentation: yeast metabolism of sulphur-containing amino acids (and intermediates like hydrogen sulphide) can produce volatile sulphur compounds.
- Distillation & copper contact: copper stills help remove some sulphur compounds, but traces may remain.
- Maturation / finishing: some VSCs fall away over time, others persist.
- Barrel history: as noted above, if barrels were treated with sulphur or stored under certain conditions, that can carry through.
A whisky’s sulphur character depends on many upstream choices — malt/fermentation, still design, cask type, finishing, age — and it’s not automatically a “fault” or a “feature”. A small whisper of sulphur can contribute complexity, while heavy sulphur often comes across as a flaw (struck match, rotten cabbage, meaty off-note).
Why some people love it while others hate it
Here’s where the real human-element comes in: our noses differ, and that means our whisky experiences differ.
Ultra-sensitivity to VSCs
Volatile sulphur compounds often have extremely low sensory thresholds, which means very little is needed for detection. Because of these very low thresholds, some VSCs exert a strong influence even when present in small amounts.
Genetic variation in smell receptors
The way our olfactory system responds is shaped by genetics. It’s kind of like an aversion to coriander (cilantro) – for those who hate it, it tastes like soap and there is no changing that impression.
What this means: if your particular set of olfactory receptors is especially sensitive to sulphur-thiols (or you express them more strongly), you may perceive a dram as “sulphury”, “meaty”, “struck match” — whereas someone else, with different receptor variants, may barely notice those notes or interpret them differently (e.g., as earthiness, peat, depth).
Context and memory also matter
Apart from genetics, familiarity, previous tasting context, and cultural/linguistic associations play a role. If you’ve had many peated whiskies and are used to “peat + smoke” you may interpret a subtle sulphur note as part of the “peaty character”. Someone new to it might find that same note off-putting, because their brain flags it as “rotten” or “struck match”.
Another factor is maturation time and balance. A whisky from a young cask with clearly strong sulphur might hit as an off-note, while in a well-balanced, matured whisky that same sulphur might be buried or softened and read as “meaty smokiness”.
Myth-busting: what people often assume — and what the science says
| Myth | Reality |
|---|---|
| Sulphur in whisky = a fault every time | Not necessarily. Some sulphur compounds at low levels contribute positive complexity. |
| If I smell sulphur, the whisky must be cheap or badly made | Not always. Many well-respected whiskies carry subtle sulphur character by design (or through barrel history) and are well-balanced. |
| Everybody perceives sulphur notes the same way | Definitely false. Genetic and experiential factors change how we perceive sulphur compounds. |
| Barrels’ sulphur is always obvious and unpleasant | Again, no. Many volatile sulphur compounds decline in maturation; some persist slowly. |
Final takeaway
If you find you loathe a particular whisky, while a friend who usually has the same taste as you loves it, you might be sensitive to sulphur. You may not even be picking up smells of struck-match or boiled-cabbage, but the hint of sulphur is enough for your senses to register it as “bad”.
The important thing to remember is that neither of you are wrong, you just have different senses. Even if you both usually enjoy the same thing.