日本語版

humulinones

compound class / compound-humulinones

フムリノン類

Oxidation products of hop alpha acid.

Photographs (captions in Japanese)

A close-up photograph of pale green, pine-cone-like hop cones

Hop cones (Humulus lupulus). Humulinones are oxidation products of hop alpha acids, and this is a photograph of the hop cones that serve as the source, not of the compounds themselves.

Raw materialShown: Humulus lupulus (hop)Part / state: Cones (hop cones)

Photo: Magdalena Šajinovićová / CC BY-SA 3.0 / original image / ledger's original image

Scope and provenance of the photo

Identification: Identified as labelled in the source.

Image shown: The full-size file from Wikimedia Commons. No cropping or color changes by NIGAMI LAB. For display, a WebP capped at 1200 px wide is served; the ledger's original image can be checked from the link above.

On this page (9 sections)
  1. Overview
  2. Sources for this overview (6)
  3. Topic hubs
  4. Follow the connections
  5. Related entries (10)
  6. Composition and content (1)
  7. Sensory (2)
  8. Mechanism and receptors (1)
  9. How processing and cooking change it (2)
↑

Reading the bitterness

Humulinones are a group of compounds produced by oxidation of alpha acid contained in hops and are positioned as one of the compounds contributing to beer bitterness. In research analyzing hop resin components, as oxidation products derived from alpha and beta acids, they are positioned as constituents of soft resin together with humolones.

Regarding contribution to beer bitterness, in predictive research on bitterness intensity with multiple non-volatile components incorporated into a model, humulinones emerged as a significant contributing factor. In research on dry hopping, while the main contributor to overall beer bitterness is stated to be iso-α-acids, humulinones and polyphenols are described as potentially having significant contribution to bitterness, particularly in beer heavily dry-hopped. Some reports state the strength of this bitterness to be approximately 66% (standard deviation 13%) of iso-α-acids, and a survey found that humulinones were detected in 117 of 121 commercially available beer brands (average 17 mg/L), which reviews consolidate as factors in the increase in perceived bitterness after dry hopping. In independent analytical chemistry research, concentration changes of humulinones through fermentation and storage processes of Double IPA dry-hopped and Vienna lager non-dry-hopped were tracked by LC-MS/MS. However, these models simultaneously contain iso-α-acids and ethanol, and do not represent isolated verification of humulinone-only effects.

Humulinone content also changes with hop storage. In research comparing 3 varieties from Slovenia across an HSI (hop storage index) range of 0.3 to 0.7, in all varieties humulinone content increased as the index rose—for example, Aurora variety increased from 0.43% to 0.69%. However, in the finished beer, when HSI thresholds that differed by variety were exceeded, humulinone concentration initially rose and then declined, which researchers explained as due to further oxidation.

Sources for this overview

  1. Analysis of the components of hard resin in hops (Humulus lupulus L.) and structural elucidation of their transformation products formed during the brewing process

    Taniguchi Y; Taniguchi H; Yamada M; Matsukura Y; Koizumi H; Furihata K; Shindo K / 2014 / journal article / abstract checked

    Checked for this overview: Confirmed classification as oxidation products derived from alpha and beta acids

  2. Evaluation of Nonvolatile Chemistry Affecting Sensory Bitterness Intensity of Highly Hopped Beers

    Hahn CD; Lafontaine SR; Pereira CB; Shellhammer TH / 2018 / journal article / abstract checked

    Checked for this overview: Confirmed description as significant contributing factor in bitterness prediction model / Confirmed modeling as contributing factor in heavily hopped beer

  3. Effects of Dry-Hopping on Beer Chemistry and Sensory Properties - A Review

    Klimczak K; Cioch-Skoneczny M; Duda-Chodak A / 2023 / review / full text checked

    Checked for this overview: Confirmed description of post-dry-hopping bitterness increase factor and 66% and 121-brand survey data

  4. Quantification of Hop-Derived Bitter Compounds in Beer Using Liquid Chromatography Mass Spectrometry

    Teng CE; Wang YM; Li TH; Chen SF / 2024 / journal article / abstract checked

    Checked for this overview: Confirmed tracking over time of Double IPA and Vienna lager by LC-MS/MS method

  5. Toward Understanding the Bitterness of Dry-Hopped Beer

    Parkin E; Shellhammer TH / 2017 / journal article / abstract checked

    Checked for this overview: Confirmed caveat regarding iso-α-acids as main contributor and potential humulinone contribution limited to heavily dry-hopped beer

  6. Impact of Hop Freshness on Dry Hopped Beer Quality

    Rutnik K; Ocvirk M; Košir IJ / 2022 / journal article / full text checked

    Checked for this overview: Confirmed conclusion as primary bitterness source in dry-hopped beer / Confirmed humulinone content increase in 3 varieties with HSI rise

Follow the connections

humulinones →contributes to→ bitterness →can be measured separately …→ astringency

beer →contains→ humulinones

humulinones →is extracted into beer by→ dry hopping

humulinones →differs from→ iso-α-acids (isohumulones) →contributes to→ bitterness

Structured claims — open a section to read each claim's confidence, evidence and limits

Composition and content (1)

beer contains humulinonessupported

Scope: Highly hopped commercial beer in the cited study

Note: Humulinones arise through oxidation and are not present in equal amounts in every beer.

Humulinones were measured in strongly hopped commercial beer and modeled as a contributor.
Limitations: Limited to a sample frame of strongly hopped beers.
Source: Evaluation of Nonvolatile Chemistry Affecting Sensory Bitterness Intensity of Highly Hopped Beers (Hahn CD; Lafontaine SR; Pereira CB; Shellhammer TH, 2018) · abstract checked
Context: Compositional analysis of hop resin identified humulinones (and hulupones) as soft-resin components and showed that both are oxidation products derived from alpha acids and beta acids. Conversion behavior in a wort-boil model was also examined. This corroborates, from an independent group (Kirin), the origin pathway of humulinones in beer (oxidation of hop acids followed by transfer during the brewing process).
Limitations: Abstract only confirmed. Since this is not a quantification of humulinones in beer itself, the relation is contextualizes (direct support for the existence claim depends on Hahn 2018).
Source: Analysis of the components of hard resin in hops (Humulus lupulus L.) and structural elucidation of their transformation products formed during the brewing process (Taniguchi Y; Taniguchi H; Yamada M; Matsukura Y; Koizumi H; Furihata K; Shindo K, 2014) · abstract checked
A group independent of the Shellhammer/OSU lineage (a Taiwanese normal university plus a brewery) developed an LC-MS/MS method that quantifies 60 hop-derived bitter compounds in 25 minutes (LOQ for humulinones 0.053 ng/mL, r>0.99, recovery 86.3-118.1%), and tracked the variation of bitter compounds including humulinones across the full fermentation and storage process for a dry-hopped Double IPA and a non-dry-hopped Vienna Lager. It also reported that the profile of oxidation and cyclization products differed between the two beers. This confirms, with independent analytical chemistry, the presence of humulinones in beer and their process dependence.
Limitations: Abstract only confirmed. Individual concentration values are not given in the abstract. No sensory data. The abstract's opening statement that the major contributors to beer bitterness are isohumulones and humulinones is part of the introduction and is not something demonstrated by this study itself.
Source: Quantification of Hop-Derived Bitter Compounds in Beer Using Liquid Chromatography Mass Spectrometry (Teng CE; Wang YM; Li TH; Chen SF, 2024) · full text checked
Show dataingredient-beer —contains→ compound-humulinones
claim: clm-beer-contains-humulinones / type: composition / updated: 2026-08-30

Sensory (2)

humulinones contributes to bitternesssupported

Scope: Highly hopped commercial beer

Note: The contribution was modeled together with isohumulones and ethanol; it is not a universal explanation by a single compound.

In a separate bitterness-prediction approach, humulinones emerged as a significant contributing factor.
Limitations: The model includes isohumulones and ethanol, so this is not a causal test of a single compound.
Source: Evaluation of Nonvolatile Chemistry Affecting Sensory Bitterness Intensity of Highly Hopped Beers (Hahn CD; Lafontaine SR; Pereira CB; Shellhammer TH, 2018) · abstract checked
Synthesis of the review: "The available literature shows that humulinones are the main factors responsible for the increase in perceived bitterness in beers after the dry-hopping process." It cites the relative bitterness of humulinones as 66% (+/-13%) of iso-alpha-acids, a report that in NEIPA most of the bitterness derives from humulinones rather than iso-alpha-acids, and a survey finding an average of 17 mg/L across 121 commercial brands and detection (>=1 mg/L) in 117 brands. This shows a convergence of the literature that humulinones are a compound class that contributes to bitterness in beer, especially dry-hopped beer.
Limitations: The cited primary data (relative bitterness 66%, the 121-brand survey — the Hahn 2018 lineage) overlaps with the Shellhammer/OSU cluster, and is not primary evidence fully independent of the existing evidence (this is a record of convergence as a review).
Source: Effects of Dry-Hopping on Beer Chemistry and Sensory Properties - A Review (Klimczak K; Cioch-Skoneczny M; Duda-Chodak A, 2023) · full text checked
Show datacompound-humulinones —contribute_to→ sensation-bitter
claim: clm-humulinones-beer / type: sensory / updated: 2026-08-30
humulinones differs from iso-α-acids (isohumulones)preliminary

Scope: A sensory panel evaluation conducted by Algazzali and Shellhammer (9 trained panelists, 0–15 point scale). The original source is a presentation at the 2015 ASBC Annual Meeting, and may not be a peer-reviewed journal article

Note: Secondhand information read in the body of the review by Klimczak et al. (2023). The original source (Algazzali & Shellhammer, 2015 ASBC Annual Meeting proceedings) itself has not been checked. The figures were copied as given in the review.

The review states that, in a 0–15 point sensory evaluation by a trained panel of 9 conducted by Algazzali and Shellhammer, humulinones were rated at a bitterness intensity of 66% (±13%) of iso-α-acids, and hulupones at 84% (±10%).
Limitations: This is secondhand information from the review; the original source (Algazzali & Shellhammer, 2015 ASBC Annual Meeting proceedings) itself has not been checked. The original is a conference presentation abstract and may not be a peer-reviewed journal article.
Source: Effects of Dry-Hopping on Beer Chemistry and Sensory Properties - A Review (Klimczak K; Cioch-Skoneczny M; Duda-Chodak A, 2023) · full text checked
Show datacompound-humulinones —differs_from→ compound-iso-alpha-acids
claim: clm-iaa-humulinone-relative-bitterness / type: sensory / updated: 2026-09-15

Mechanism and receptors (1)

humulinones differs from iso-α-acids (isohumulones)supported

Scope: The kettle-hopping experiment in Rutnik 2023 (a comparison at the same HSI with different boiling times)

Comparing samples with the same HSI but different boiling times, humulinone concentration changed only slightly with differences in boiling time, whereas iso-α-acid concentration increased clearly with boiling time. From this it was concluded that humulinones have lower thermal stability than iso-α-acids, and that iso-α-acid formation requires a high temperature.
Limitations: The conclusion of 「熱安定性が低い」 (in translation: "lower thermal stability") is an inference from the trend in concentration change, not a direct measurement of humulinones' own thermal decomposition rate.
Source: The Impact of Hop Freshness on Kettle-Hopped Beers (Rutnik K; Ocvirk M; Košir IJ, 2023) · full text checked
Show datacompound-humulinones —differs_from→ compound-iso-alpha-acids
claim: clm-iaa-humulinones-less-thermally-stable / type: mechanism / updated: 2026-09-15

How processing and cooking change it (2)

humulinones is extracted into beer by dry hoppingsupported

Scope: Dry-hopped beer in a pilot-scale study, a survey of 15 commercial brands, and a hop-freshness trial across 3 varieties

While iso-α-acids were the main contributor to beer bitterness overall, humulinones (oxidized α-acids) and polyphenols were also potentially significant contributors to bitterness, especially in strongly dry-hopped beers, and the IBU increase from dry hopping was attributed to the extraction of humulinones.
Limitations: Abstract-level extraction. The phrase 'potentially significant' is the authors' own hedge and is preserved here as well. The abstract reports no omission/addition test with isolated compounds.
Source: Toward Understanding the Bitterness of Dry-Hopped Beer (Parkin E; Shellhammer TH, 2017) · abstract checked
The introduction states, 'For a long time, dry hopping was not considered to contribute to bitterness, since no isomerisation of alpha acids occurs,' and states that humulinones are oxygenation products of α-acids, that their concentration increases during hop storage, and that they carry approximately 66% of the bitterness of iso-α-acids. The conclusion states, 'In dry hopped beers, the main source of bitterness is humulinones, which are increasing and, at a certain HSI, started to drop; this is due to the further oxidation of humulinones to oxidation products.'
Limitations: The figure '66% of the bitterness of iso-α-acids' and its historical framing are cited from prior literature within this paper's introduction, not measured in this study, so it is recorded as context and not promoted to a claim. The description 'main source of bitterness' is the authors' conclusion about dry-hop-only beers and is not generalized to kettle-hopped beers.
Source: Impact of Hop Freshness on Dry Hopped Beer Quality (Rutnik K; Ocvirk M; Košir IJ, 2022) · full text checked
The review writes 「静置型(static)のドライホッピングでは、24時間で平均75%のフムリノンが13.3-15.0°Cの工程温度で抽出されるのに十分」 (in translation: "in static dry hopping, 24 hours is sufficient for an average of 75% of humulinones to be extracted at a process temperature of 13.3-15.0°C") (citing Lafontaine and Shellhammer).
Limitations: These are figures from a primary study (Lafontaine and Shellhammer) cited by the review; this entry has not checked the primary paper itself. They cannot be generalized to dynamic (agitated) dry hopping (the authors themselves specify static).
Source: Effects of Dry-Hopping on Beer Chemistry and Sensory Properties - A Review (Klimczak K; Cioch-Skoneczny M; Duda-Chodak A, 2023) · full text checked
Show datacompound-humulinones —is_extracted_into_beer_by→ process-dry-hopping
claim: clm-humulinones-dry-hop-extraction / type: processing / updated: 2026-08-30
humulinones increases in hops with A rise in the hop storage index (HSI). From HSI 0.3 to 0.7, humulinone content rose from 0.11 to 0.18% (Celeia), 0.43 to 0.69% (Aurora), and 0.42 to 0.72% (Styrian Wolf)supported

Scope: 3 hop varieties from Slovenia, at 5 HSI levels (0.3, 0.4, 0.5, 0.6, 0.7)

Note: The direction is consistent across all 3 varieties. In the resulting beer, humulinone levels rose and then fell once a variety-dependent HSI was exceeded, which the authors attribute to further oxidation.

Humulinone content (%) rose with the hop storage index across all 3 varieties between HSI 0.3 and 0.7: 0.11 +/- 0.01 to 0.18 +/- 0.01 (Celeia), 0.43 +/- 0.03 to 0.69 +/- 0.04 (Aurora), 0.42 +/- 0.03 to 0.72 +/- 0.05 (Styrian Wolf). In the finished beer, humulinone concentration rose and then turned to decline once a variety-dependent HSI was exceeded, which the authors attribute to further oxidation of humulinones.
Limitations: The percentage values are content in the raw hop material, not concentration in the beer. HSI levels were obtained separately for each variety, and the paper does not report replicate brews for each cell. Because the absolute amount of humulinone differs by roughly a factor of 4 between varieties, what matters is the common direction rather than the magnitude.
Source: Impact of Hop Freshness on Dry Hopped Beer Quality (Rutnik K; Ocvirk M; Košir IJ, 2022) · full text checked
Show datacompound-humulinones —increases_in_hops_with→ (the claim sentence above)
claim: clm-hop-storage-raises-humulinones / type: processing / updated: 2026-08-30

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