Hop variety · 🇺🇸 US
Comet
Lemongrass grapefruit geranium resin. Bred by USDA, released 1974, modern revival.
- Alpha acid
- 8–10.5 %
- Total oil
- 1.4–3.3 mL/100 g
- 3MH-family thiols
- Significant
- 4MMP
- Low
- Data
- Supplier reference
Aroma in one line
Brewers describe Comet as lemongrass grapefruit geranium resin. In Hoparoma's hop notes its thiol character is filed as wild grapefruit. Part of its fruit character comes from bound thiol precursors; the rest rides on the oils listed below.
Brewing values
Typical ranges come from supplier datasheets and lot certificates; the median column pools 7 published sources. Oil fractions are percent of total oil.
| Measure | Typical range | Median |
|---|---|---|
| Alpha acid % | 8–10.5 | 9.5 |
| Beta acid % | – | – |
| Cohumulone % of alpha | – | – |
| Total oil mL/100 g | 1.4–3.3 | 2 |
| Myrcene % | 40–65 | 52 |
| Humulene % | 1–2 | 1.5 |
| β-Caryophyllene % | 5–7 | 6 |
| Farnesene % | 1–1.5 | 1.3 |
| β-Pinene % | – | 0.8 |
| Linalool % | 0.4–1 | 0.7 |
| Geraniol % | 0.2–1 | 0.6 |
Range source: 2026-06 YCH+Haas aggregate (3MH grapefruit).
Thiol potential
Most of a hop's thiol aroma sits in the cone as odourless precursors bound to cysteine or glutathione; free thiols are a small fraction of the pool Gros et al. 2012 Kishimoto 2009. The tiers above summarise published precursor measurements and supplier statements for this variety. They are qualitative on purpose: Hoparoma's internal weighting is not published, and lot-to-lot variation is large.
Which yeast brings it out
A medium or high β-lyase strain, such as the London III family, LalBrew Pomona, or any of the thiol-forward strains, brings out the bound fraction. A clean Chico-type strain leaves it mostly bound, which is fine if you want the oil-driven character alone.
Rule of thumb only. See the yeast table for every strain's rating and the literature behind it.
In Hoparoma
Hoparoma computes how much of Comet's aroma compounds survive your boil, whirlpool, and dry hop, and models the thiol side across yeast, hop, malt, and Phantasm together. The result is a research-based estimate of where the beer is likely to land, not a guarantee.
Free in any browser, 3 recipes a month. What the calculator does
Sources and data quality
- Data quality: Supplier reference (2026-06 YCH+Haas 3MH-grapefruit)
- Typical ranges: 2026-06 YCH+Haas aggregate (3MH grapefruit)
- Thiol background: Gros et al. 2012, Kishimoto 2009, Takoi et al. 2009, Roland et al. 2016
- Supplier references: Yakima Chief Hops, Hop Products Australia, BarthHaas, NZ Hops, Hop Alliance
Full list with links on the sources page. Spotted an error? Tell us and we will correct the dataset in the next release. This page's tables are published under CC BY 4.0; reuse with credit and a link.