4-Methylphenol
Also written p-cresol, para-cresol
Quick answer
A faecal, horse-stable smelling phenol that forms when white pepper is retted, and one of the two compounds most responsible for the off-odour of poor white pepper.
What it does
At the sniffing port 4-methylphenol smells faecal and horse-like. Together with 3-methylindole it carried the highest flavour dilution factors in a white pepper powder with a strong cowshed-like off-flavour, and odour activity values calculated from orthonasal breakthrough thresholds placed it among the main sources of that defect, with 3-methylphenol and butanoic acid.
How it behaves when cooked
Four properties of the molecule, and what they mean at the stove.
- Volatility
- moderate
- Fat solubility
- moderate
- Water solubility
- moderate
- Heat stability
- moderate
Like 3-methylindole it is formed biochemically during retting, the soak that loosens the skin of the pepper berry, and it is largely avoidable: ripe berries fermented briefly under water with frequent water exchange gave white pepper without substantial amounts of the off-odorants and with a better overall aroma than the traditional process. What a buyer can control is age: in ground white pepper the off-note strengthened over seven months while the off-odorants stayed roughly constant, as the masking top notes evaporated.
Spices that carry it
Recorded on the compound rather than on each spice, so the two cannot disagree.
Reported as formed during retting, on measurements of pepper taken from one retting batch at a Thai plant and read here in the abstract only, which does not say what the berries held beforehand. It is a processing fault, not part of white pepper’s intended aroma.
Not to be confused with
Compounds a reader is likely to take for this one, and why they differ.
3-Methylindole
Formed alongside it in retting white pepper. Both are faecal; 3-methylindole reads as swine manure, 4-methylphenol as a horse stable.
Guaiacol
Another small phenol, but a compound of smoke and of hard roasting: guaiacol in a smoke-dried spice comes from burning wood, 4-methylphenol in white pepper from fermentation.
Questions this page answers
- what causes the off smell in white pepper
- what is 4-methylphenol in white pepper