methanethiol

sulfurous thiol Key food odorant

Found in 492 ingredients across the CompKitchen flavor graph.

Look up another compound — search by name, CAS number, PubChem CID, or FEMA #.

2D Lewis Structure

Formula: CH4S
Molecular weight: 48.11 g/mol
PubChem CID: 878 — full record on PubChem

Key food odorant (intermediary)

Dunkel et al. 2014

Identified in the meta-analysis of 227 food samples as one of 57 intermediary odorants — appears in 5–25% of foods.

Source: Angew. Chem. Int. Ed. 2014, 53, 7124–7143

Properties

Odor description: sulfur, cabbage, garlic
Odor threshold — orthonasal, in clean water: 0.020 ppb – 0.110 ppb median 0.065 ppb · 2 published values · see all 16 with sources
Volatility: high
CAS number: 74-93-1
Retention index: 3

Not in FEMA GRAS publications 1-33. Of 3,367 listed flavoring substances, none match this compound name. May still be food-safe under other regulatory routes (FDA 21 CFR 172, EFSA, JECFA) — check femaflavor.org for the authoritative current list.

How this molecule is described

Sources disagree about odour more often than they disagree about chemistry. Rather than show one answer, here is every description on file with how many ingredient records carry it.

Also filed as

methyl mercaptan

Same molecule, unified here — previously counted and displayed as separate compounds.

Descriptions on file

Ordered by how many independent descriptor streams give each wording, then by how often it appears. The bar is still replication — one source copied onto many ingredients scores high there — so the two can disagree.

sulfur, cabbage, garlic shown above Flavornet Cas, Flavornet Name, Flavordb Odor Column 3 sources agree

—

decomposing cabbage, garlic, gasoline, sulfur FlavorDB 2.0

423

sulfur, gasoline, garlic, decomposing cabbage FlavorDB 2.0

reductive aroma, unpleasant FlavorDB 2.0

cooked FlavorDB 2.0

rotten, sulfurous FlavorDB 2.0

Bars are the share of ingredient records carrying each description. High agreement means the sources replicate each other — not necessarily that they are right.

Published thresholds

16 measured values from the literature. Grouped by what was actually measured — a threshold smelled in clean water, tasted in the mouth, or measured in a real food are three different quantities and are not pooled.

Orthonasal, in clean water

0.020 ppb – 0.110 ppb

The reference measurement — smelled in water. OAV is computed against this.

Threshold	Matrix	Source	Paper
0.020 ppb	water_odor	Leffingwell	—
0.110 ppb SIDA	water	Rychlik 1998 · 2 studies	—

In a food matrix

0.350 ppb – 232 ppb

Measured in a real food, where the matrix shifts detection — not a clean-water value.

Threshold	Matrix	Source	Paper
0.020 ppb	water (food: reference standard (water))	Literature corpus	22059567, 22416694, 31554058 +3
Flagged: 150× from the median of this group. Excluded from the range above pending re-check against the source publication — shown rather than hidden.
0.350 ppb	water (food: rice)	Literature corpus	22059567, 22416694, 31554058 +3
0.590 ppb	water (food: green tea infusion (jingshan cha))	Literature corpus	22059567, 22416694, 31554058 +3
0.590 ppb	water (food: longjing green tea infusion)	Literature corpus	22059567, 22416694, 31554058 +3
3.0 ppb	water (food: fish)	Literature corpus	22059567, 22416694, 31554058 +3
8.8 ppb	water (food: lime)	Literature corpus	22059567, 22416694, 31554058 +3
45.0 ppb	water (food: unknown)	Literature corpus	22059567, 22416694, 31554058 +3
153 ppb	water (food: chicken)	Literature corpus	22059567, 22416694, 31554058 +3
232 ppb	water (food: tea)	Literature corpus	22059567, 22416694, 31554058 +3

Retronasal / in-mouth

0.340 ppb – 2.0 ppb

Tasted rather than smelled — a different sense, not comparable.

Threshold	Matrix	Source	Paper
0.340 ppb SIDA	oil_retronasal	Rychlik 1998 · 1 studies	—
2.0 ppb	water_flavor	Leffingwell	—

In air

0.0007 ppb – 0.070 ppb

Airborne detection — not comparable to a water threshold.

Threshold	Matrix	Source	Paper
0.0007 ppb	air (food: reference standard (air))	Literature corpus	22059567, 22416694, 31554058 +3
0.070 ppb	air	Nagata 2003	—

Other matrix

0.060 ppb

Measured in a non-aqueous medium (oil, starch, cellulose).

Threshold	Matrix	Source	Paper
0.060 ppb SIDA	oil_orthonasal	Rychlik 1998 · 1 studies	—

Only values we can attribute are listed. Where a compendium's licence does not permit public attribution its figures are omitted here, so every number on this page traces to a citable source.

Where you'd actually smell it

Odor Activity Value = measured concentration ÷ odor threshold (0.59 ppb, the engine's canonical value — see the 16 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
black tea	300000.0	508475 ⚡	—
beef	1000.0	1695 ⚡	Corpus paper
tea	231.4	392 ⚡	Corpus paper
sab	68.5	116 ⚡	Corpus paper
lime	12.5	21.1 ⚡	Corpus paper
fish	1.0	1.69	Corpus paper
garlic	0.1	0.12	PMID 37301918
rice	0.0	0.04	Corpus paper

Concentrations from PubMed Central Open Access papers (free literature corpus, MIT-style licensed). Copper = OAV ≥ 10 (strongly perceptible). Green = OAV ≥ 1 (perceptible).

Found in

Measured impact first, then profile share

Every ingredient known to contain methanethiol. Ingredients with a measured concentration come first, ranked by odour activity; the rest follow by how large a share of that ingredient's profile this molecule is. The figure beside each is how many different compounds that ingredient has in total — not the concentration of methanethiol in it. Full concentrations are in the OAV table above.

black tea

measured · OAV 508474.58

586 cmpds

beef

measured · OAV 1694.92

451 cmpds

617 cmpds

301 cmpds