Does Flower Storage Time Change Ylang-Ylang Essential Oil?

Ylang-ylang flowers do not become essential oil the moment they are picked. They must be transported from the field and may wait for distillation equipment to become available. How much can that waiting time change the amount and composition of the oil obtained?

In a study published in 2026, Abacar Chakira and colleagues separately investigated flower-storage duration before distillation and the time of day when flowers were harvested. Their aim was to clarify how harvesting, transport, and distillation schedules at the production site relate to ylang-ylang essential-oil yield and composition.

When should picked flowers be distilled?

The study used fully mature ylang-ylang flowers grown on the French island of Réunion. In the storage experiment, flowers picked at 7 a.m. were divided into 100 g portions and distilled immediately or after four, eight, 24, or 30 hours. Each condition was tested three times.

During storage, flowers were spread thinly on a shaded bench without compression and with natural ventilation. Air temperature was about 24–33°C and humidity 48–86%. This was not an experiment on refrigerated flowers or flowers packed into bags.

The flowers were heated with water and extracted for three hours from the first oil-containing drop. The recovered essential oil was weighed, and its volatile constituents were separated and examined using GC–MS.

Lighter flowers do not necessarily yield more oil

The flowers lost substantial mass as storage continued: about 34% of their initial mass after eight hours and about 70% after 30 hours. The authors attribute most of this decrease to water evaporation.

By contrast, oil yield based on flower mass before storage was 0.78% with immediate distillation, and 0.76% after both four and eight hours. It was 0.73% after 24 hours and 0.72% after 30 hours. Drying made the flowers lighter but did not increase the oil recovered from the original batch.

The study reports that yield was relatively maintained through eight hours and was lower after 24–30 hours. These are means from a small number of replicates, however, not figures that can be applied unchanged to every origin or storage condition.

Longer waiting also changed the balance of constituents

The composition analysis compared each constituent’s peak as a proportion of the total detected peak area. An increase in a constituent’s proportion does not necessarily mean that more of that constituent was produced. It can also appear relatively larger when other constituents decrease.

With that distinction in mind, storage effects were not uniform. Benzyl acetate represented about 28% in immediately distilled oil but about 11% after 24–30 hours. Methyl benzoate and p-cresyl methyl ether also had lower proportions after longer storage.

Conversely, benzyl benzoate, benzyl salicylate, and germacrene D, among others, became relatively more abundant in oil from flowers stored longer. No clear storage-duration difference was detected for linalool. The result was therefore not that all odor-related constituents declined at the same rate.

The authors highlight a decline in relatively light, readily volatile oxygenated compounds and an increase in the proportion of heavier compounds and hydrocarbons. Oxygenated compounds contain oxygen in their molecules and include esters and alcohols.

How much was established about changes in odor quality?

Drawing on the known odor characteristics of compounds such as benzyl acetate, the paper discusses the possibility that prolonged storage weakens bright floral and fruity impressions and changes their balance with heavier, more persistent aspects of the scent. This is the authors’ interpretation of the compositional changes.

The study did not have people smell the oils and score their vividness or pleasantness. Changes in compound proportions therefore cannot be translated directly into a percentage reduction in scent strength or a conclusion that quality declined for everyone.

Possible explanations for compositional changes include continued respiration after picking, moisture loss, evaporation, oxidation, and degradation. However, the study did not track each reaction directly, so their individual contributions remain uncertain.

A separate experiment varied the harvest time

In another experiment, flowers were picked from the same tree at 7 a.m., 11 a.m., and 3 p.m. and distilled immediately. Each condition again had three replicates. This experiment was conducted at a different nearby site and in a different year and seasonal period from the storage experiment, so the two cannot be treated as a combined experimental design.

Mean yields were 0.81% at 7 a.m., 0.77% at 11 a.m., and 0.80% at 3 p.m. Composition also varied with harvest time. The 11 a.m. oil reportedly tended to have a lower proportion of relatively light oxygenated compounds and a higher proportion of heavier oxygenated compounds. Not every individual constituent differed by time of day.

The authors suggest that morning accumulation, daytime evaporation, and flower metabolism may be involved and recommend harvesting during cooler hours. However, the experiment did not vary temperature alone. It did not establish a universal clock-based rule that 11 a.m. is inherently unfavorable.

Organizing the flow of flowers, not just the distillation equipment

The practical significance is the focus on the whole process from picking to distillation, rather than only extraction-equipment performance. The authors conclude that processing as quickly as possible, with eight hours as a guide under the tested conditions, matters for maintaining yield and a desirable composition.

At production sites, transport routes and equipment capacity affect waiting time. The authors also point out that bagging or piling flowers could add compression and inadequate ventilation, potentially causing greater effects than under the thinly spread conditions used here. This is a prospect requiring field verification, not a result directly compared in this experiment.

The study was supported by Campus France, the French Embassy in the Comoros, and the European Union and Réunion Region’s Interreg-V Qualinnov 2 project. The authors declared no conflicts of interest.

Summary

In experiments using flowers from Réunion, waiting 24–30 hours before distillation changed oil recovery and the balance of constituents compared with conditions within eight hours. A separate experiment comparing harvest times also found differences in yield and composition.

Although the study did not directly rank the odors perceived by people, it shows that an essential oil’s characteristics are not determined solely inside the still. Designing harvesting, transport, waiting, and distillation as a connected process is an important challenge in transferring flower characteristics consistently into the oil.

References

Chakira, A., Soria, C., Minier, J., Chillet, M., & Garcia, C. (2026). Effect of Flower Storage and Harvest Times on the Dynamics of Volatile Compounds in Ylang-Ylang [Cananga odorata (Lam.) Hook.f. &Thomson] Essential Oil. Plants, 15(6), 891. DOI: 10.3390/plants15060891 / Full text. Original article license: CC BY.