Up to 80% of your hop oils, particularly β-myrcene, may be lost during dry hopping due to poor solubility and re-adsorption. However, with smarter practices, you can retain far more of that aroma, explains Francesco Lo Bue, an agronomist with a degree in food technology, specialised in hops aromatic compounds, and a brewer with 10 years of experience in the most technological craft breweries in Europe and the UK.

β-myrcene is a monoterpene hydrocarbon, chemically related to compounds found in mango, basil, and cannabis, which share its earthy, dank, or fruity tones.

However, because it’s volatile, water-insoluble and has a relatively high flavour threshold (~350 µg/L), its impact depends on how much makes it into the finished beer.

The brewers’ goal is to optimise dry-hopping to capture as much of this hop oil as possible, balancing process factors like hop variety, temperature, contact time, alcohol content and hop type.

Hop Essential Oils and β-Myrcene Solubility

Hop essential oils are complex (≈1000 compounds) but are often divided into hydrocarbon fraction such as monoterpenes like β-myrcene, sesquiterpenes and oxygenated aromatics like terpene alcohols and esters.

Hydrocarbons dominate by volume, but their hydrophobicity means they transfer poorly into beer. For example, after 24 h dry hopping, only 33–51% of the hops’ total oil had left the hops, and nearly all of that was oxygenated oil (i.e. linalool), whereas β-myrcene and other hydrocarbons were largely retained in the spent hops Salamon et al. (2022).

 In practical terms, this means polar aromatics dissolve readily, but β-myrcene often stays on the plant material or escapes to the air.

Dry-Hopping Efficiency and β-Myrcene Yield

Even with optimised dry-hopping, studies show only a small fraction of the hops’ β-myrcene dissolves. Salamon et al. (2022) directly measured β-myrcene in beer during dry hopping.

Using grinded pellet hops blended into fermenting beer, they found β-myrcene peaked at 301 μg/L after ~34 h, then slowly settled to ~215 μg/L by ~44 h.

Critically, this represented only 8% dissolution efficiency (fraction of hop oil recovered) at its maximum.

What’s very interesting and concerning is that the spent hops still contained the majority of their volatiles after dry hopping – up to 50–80% of hop acids and 70–80% of hydrocarbons remained unused.

Measured concentrations peaked after ~34 h, indicating that longer contact can even decrease β-myrcene, suggesting hydrophobic compounds can re-bind to spent hops over time.

Extraction Timeline

Hydrocarbon terpenes (including myrcene) peak at 3–6 h and then decline over 24 h when agitating the beer in a pressurised tank.

High dry hopping rates in dynamic tests show myrcene hits its maximum by 3–6 h at 20 °C and then falls off. Thus, contrary to practices of multiple-day dry-hops, current evidence suggests 24–36 h is usually enough to saturate β-myrcene extraction.

Effects of Process Variables

• Temperature and Agitation: Higher fermentation or conditioning temperatures (≥15–20 °C) dramatically speed β-myrcene release, as higher diffusion and solubility occur.|
  However, warmer temperatures also increase losses, showing significantly more β-myrcene evaporates with CO₂ at 22 °C than at 8 °C.
  
  
• Contact Time: As noted, hydrocarbon terpenes extract rapidly and then level off or decline. I would recommend relatively short dry-hops for volatile aroma not exceeding 48 hours, and in case of a dry-hopping system that allows higher contact surface than the most common methods, 24 hours is enough.
  
  
• Alcohol Content: Ethanol greatly enhances hop oil solubility and in practice, the typical 5–8% range of beer ABV is more than enough to dissolve all extractable myrcene from dry hops.
  
  
• Hop Form and Variety: Hop variety and pellet processing set the potential; a high-myrcene hop (like Citra, with ~40–70% of its oil as myrcene) will release more myrcene than a low-myrcene variety but even pellet grade matters, a Hallertau Tradition T45 pellet contains ~60% more β-myrcene than the traditional T90 pellet.
  
  
• Hop Dose: More hops mean more aroma up to a point, but with diminishing returns. Dry-hop extractions are nonlinear: doubling the hop dose will not double the beer’s aroma. Each incremental amount of hops yields less new flavour because the beer can only absorb a finite amount of oil and more hops can also re-adsorb volatiles.
  
  

Best Practices

Based on the above, brewers can adopt these guidelines to maximise β-myrcene aroma:

• Use High-Oil Pellets: Select hop varieties known for high β-myrcene (i.e. Citra, Mosaic and Simcoe) and consider enriched pellet types to maximise oil content.
  
  
• Maximise Contact Surface: Consider bubbling CO2, recirculation or mixing in an external vessel hops and part of your beer before reintroducing it in the origin tank.
  
  
• Optimise Contact Time: Plan for 24-48 hours of contact. Many key terpenes are extracted in the first 12–24 h; beyond ~36-48 h, gains are minimal
  
  
• Control Temperature: Dry hop at cool-to-moderate temperatures (i.e. 12–18 °C) to balance extraction rate against losses.
  If speed is needed, one can increase the temperature briefly, but then reduce contact time before extensive evaporation.
  
  

Up to 80% of your hop oils, particularly β-myrcene, may be lost during dry hopping due to poor solubility and re-adsorption. However, with smarter practices, you can retain far more of that aroma.

For further brewing science insights or enquiries, feel free to get in touch at francesco@brewingtrade.com