Distillation of pure essential oils is principally performed using two methods: True Steam Distillation and Steam & Water Distillation. A third method, called Water Distillation, is when the plant material is mixed with water and the mother flask is heated directly to boil the water. This method has fallen out of favor due to possible pyrolysis (the burning of the plant material) and degrading the oil quality.
Steam Distillation (SD): The steam distillation process is essentially when the plant material in the mother flask is not mixed with water and the essential oil is extracted by steam injection into the dry plant material.
Steam & Water Distillation (WD): This process is utilized when water is needed to create more contact with the surface of the plant material through the boiling of the water; however, the heat source is still from an injection of steam and not directly boiled, therefore avoiding the scorching of the plant material.
Average Essential Oil Distillation Yields by Weight
These are approximate yields based on the weight of dried plant materials. Distillation of fresh plant material will yield significantly different results by weight due to high water content in the fresh materials.
| Plant | Botanical Name | Source | Method | % Yield |
| Basil, Sweet | Ocimum basilicum | leaves | SD | 0.5 |
| Carrot Seed | Daucus carota | seeds | SD | 0.2-0.5 |
| Cedarwood | Cedrus atlantica | chips | SD | 4.5 |
| Chamomile, Roman | Anthemis nobilis | flowers | SD | 0.3-1.0 |
| Cinnamon Bark | Cinnamomum zeylanicum | inner bark | SD | 0.5-0.8 |
| Clary Sage | Salvia sclarea | leaves/tops | SD | 9.0 |
| Clove Bud | Eugenia caryophyllata | flower buds | SD | 15-17.0 |
| Eucalyptus | Eucalyptus globulus | leaves/stems | SD | 1.0-7.0 |
| Geranium | Pelargonium graveolens | leaves | SD | 0.3-2.0 |
| Ginger | Zingiber officinale | rhizome | SD | 1.5-3.0 |
| Helichrysum | Helichrysum angustifolium | flowers | SD | 0.3-0.5 |
| Hyssop | Hyssopus officinalis | leaves/tops | SD | 1.0 |
| Juniper Berry | Juniperus communis | berries | SD | 1.5 |
| Lavender | Lavandula angustifolia | flower tops | SD | 0.5-1.0 |
| Lemongrass | Cymbopogon citratus | leaves | SD | 1.0 |
| Lime | Citrus aurantium | fruit rind | SD | 9.0 |
| Marjoram | Origanum majorana | leaves | SD | 0.9 |
| Nutmeg | Myristica fragrans | seeds | SD | 15-25.0 |
| Oregano | Origanum vulgare | leaves | SD | 1.2 |
| Patchouli | Pogostemon cablin | leaves | SD | 1.6-3.6 |
| Peppermint | Mentha piperita | leaves/tops | SD | 1.0-2.5 |
| Pine Needle | Abies sibirica | needles | SD | 0.5-3.0 |
| Rosemary | Rosmarinus officinalis | flower top | SD | 0.5-1.1 |
| Sage | Salvia officinalis | leaves | SD | 2.5 |
| Spearmint | Mentha spicata | leaves/top | SD | 2.0 |
| Vetiver | Vetiveria zizanoides | root | SD | 0.9 |
| Wintergreen | Gaultheria procumbens | leaves | SD | 0.6 |
| Ylang-Ylang | Cananga odorata | flowers | SD | 2.0 |
Essential Oil Yields
Distillation yields of pure essential oils vary with each distillation due to changes in the soil, weather patterns, the time of year, the time of the plant cutting, and the time before its actual distillation. The yields shown above are meant as guidelines and will seldom match exactly. As you can see, it takes a great deal of plant material to obtain the precious essential oils.
Note: The information provided on this site is for educational purposes only and is not intended to assess, diagnose, or prescribe for any medical condition. Always seek the counsel of a qualified holistic health care practitioner for concerns.
