Examine creator Kenny Wee Ting Lee with “libex” espresso within the Higher Baram Valley, Sarawak, Malaysia. Picture by Rave Solar Kwok, courtesy of Royal Botanic Gardens, Kew.

Researchers from the Royal Botanic Gardens, Kew, have proposed the formal identify Coffea × libex for hybrids of the liberica and excelsa espresso species, arguing that the cross may present a commercially viable pathway for espresso manufacturing as local weather change intensifies.

Printed in Scientific Stories as an early-access article on Could 14, the examine notes that espresso growers in Sarawak, Malaysia, and components of Southeast Asia, India and Central America have been cultivating the hybrid for years with out figuring out it as such. 

Aaron P. Davis, a Royal Botanic Gardens, Kew scientist and corresponding creator of the brand new paper, additionally led a 2025 Nature Crops examine that helped outline liberica and excelsa as separate species. Excelsa had traditionally been handled as a wide range of liberica, whereas arabica and robusta collectively proceed to account for greater than 99.99% of the world’s espresso.

Mixed, the research recommend liberica, excelsa or their newly named hybrid, libex, could provide focused options to the world’s two dominant business espresso species, arabica and robusta, as local weather change reshapes world espresso manufacturing. 

The New Analysis

The brand new examine concerned genomic evaluation of seven,618 single nucleotide polymorphisms — tiny variations in DNA that act as genetic fingerprints — throughout 113 plant samples collected from farms and germplasm collections on three continents. 

The workforce confirmed in depth hybridization between liberica and excelsa in cultivated vegetation, regardless of huge separation between the species’ wild populations, suggesting that the libex hybrid emerged by way of cultivation, seed motion or each.

Libex espresso with darkish crimson fruits and teardrop-shaped seed. Picture by Kenny Wee Ting Lee, courtesy of Royal Botanic Gardens, Kew.

The prevalence of admixture — the technical time period for the proportion of every guardian’s genetic materials in a hybrid — was particularly outstanding on farms studied in Sarawak, Malaysia.

Of the 45 Sarawak accessions labeled as liberica, 40 confirmed measurable excelsa admixture, and 28 exceeded 12% admixture. Solely 5 have been genetically “pure” liberica. Admixed vegetation have been additionally present in India, Indonesia, Costa Rica and Uganda, suggesting a number of unbiased hybridization occasions or the unfold of hybridized seeds and vegetation throughout areas.

Understanding Libex

Dimension and Processing Necessities

Subject observations in Sarawak confirmed that vegetation with excessive ranges of excelsa admixture had extra flowers and fruits per department, thinner fruit pulp and smaller seeds than typical liberica. In response to the analysis workforce, such properties could possibly be manipulated by way of hybridization to enhance variables equivalent to yield, post-harvest processing necessities and “outturn,” the conversion ratio of picked cherry to inexperienced espresso. 

As a sensible instance, a libex hybrid that inherits excelsa’s naturally thinner parchment or pulp may enhance outturn and cut back post-harvest processing time, doubtlessly enhancing farmer profitability.

Local weather Resilience

As for local weather resilience, liberica is thought to be extra tolerant of sure sizzling, moist and low-elevation rising situations the place arabica or robusta could wrestle. Excelsa is extra productive and simpler to course of however seems much less tolerant of utmost situations.

In response to the researchers, a hybrid with traits from each may doubtlessly be grown in environments the place neither guardian alone would succeed.

Variation in libex espresso hybrids. Picture by Kenny Wee Ting Lee, courtesy of Royal Botanic Gardens, Kew.

Illness Resistance

On illness, the paper is cautiously optimistic. Liberica carries the SH3 gene, believed to offer resistance to most strains of espresso leaf rust. Subject observations in Sarawak confirmed zero to negligible rust incidence on each pure liberica and libex vegetation, regardless of rising situations that will favor rust growth.

Whether or not that resistance would persistently switch by way of hybridization stays a query — one recognized by the authors for future work.

Taste and Cup Qualities

In a media abstract of the paper, the authors famous that liberica has an unfamiliar taste that may be “difficult” to many espresso drinkers. The paper notes that it’s typically recognized by daring tropical fruit flavors with low acidity and excessive sweetness. In the meantime, excelsa espresso is “dominated by notes of darkish, dried fruits (currant, prune, plum, fig), chocolate (cacao nibs, darkish and milk chocolate), and spices” with low to medium acidity and low bitterness. 

The researchers mentioned libex coffees from Sarawak appeared to mix taste qualities from each guardian species whereas muting their extremes. Nevertheless, the researchers famous that “rigorous sensory analysis throughout a number of environments and processing strategies will likely be required to substantiate these preliminary impressions.”

Feedback? Questions? Information to share? Contact DCN’s editors right here. For all the most recent espresso business information, subscribe to the DCN publication.