[3] It is also frequently present in bio-oil produced by pyrolysis of lignocellulosic biomass.
[4] It is produced along with 4-ethylphenol (4-EP) in wine and beer by the spoilage yeast Brettanomyces.
[3] When it is produced by the yeast to concentrations greater than the sensory threshold of >600 μg/L, it can contribute bacon, spice, clove, or smoky aromas to the wine.
The ratio in which 4-EP and 4-EG are present can greatly affect the organoleptic properties of the wine.
It is produced from the lignin, along with many of the other phenolic compounds present in bio-oil.