A molecule is one chemical compound. SmellBook lists geosmin because a VERIFIED claim names it in the evidence for 1 Atlas entry: Soil.
What it is
These identifiers pin down exactly which compound is meant, so the same molecule can be found in other databases. They say nothing about how it smells.
Checked against PubChem and Wikidata on 2026-10-06 by an automated identifier check. Every name SmellBook uses must resolve to the same single PubChem compound.
Where research reports it
Each report below is a VERIFIED claim, quoted with its scope and the source it rests on. The role says what the claim states about the molecule, in the claim’s own words.
Key odorant · the claim says “responsible for the characteristic odour of moist soil”
The claim names it among the molecules that matter most for the smell of what was studied.
The earthy-smelling substance geosmin, isolated from several actinomycetes, is described by biochemical research on the soil organism Streptomyces coelicolor as responsible for the characteristic odour of moist soil.
Scope: Laboratory cultures and a study of the enzyme that makes geosmin; the 2007 study states the link to soil odour as background and did not test it, and neither source measured the air above soil or which other compounds contribute to its smell.
Any cause and effect beyond the claim's own words. SmellBook does not add that the molecule causes, or is, the smell of an entry; most smells come from many compounds together.
How the pure molecule smells on its own. SmellBook does not describe the odour of single molecules in its own words; a claim may only quote what a study's assessors noted.
How much of it there is, or whether people can smell it at the amounts measured, unless a claim says so.
That it is absent from smells not listed here. A missing entry means no registered claim names it there.
Anything about safety or health.
WHAT THIS MEANS
SmellBook lists a molecule only where a VERIFIED claim names it, in the role and scope that claim states. A molecule reported in a smell's evidence is not the whole smell: most smells come from many compounds together, and the studies measured particular samples, such as one cultivar, an essential oil or a cooked product.