This is a the first run of my small scale back yard set up on various geraniums distilled for hydrosol, using a pump to reticulate water through the condenser to save water. It means I do not have to stay close by every second for two or more hours. (I am still in the vicinity though in case of mishaps!)
Harvest of lemon geranium (Pelargonium crispum) this morning, stripped leaves from branches (approx 500gm plant material) and added to 3 litres of commercially distilled lemon geranium hydrosol so I get double the benefit. I don't extract any essential oil out of it.https://youtu.be/LFVPV6WHCIg. I achieved about 600 ml good quality hydrosol after 3 hours on the hot plate. (leaf 1 in picture below)
First up is rose geranium (Pelargonium graveloans var. roseum) with pure water (leaf 2 in picture below). Hydrosol appeared very quickly and prolifically, obtaining 200 ml within first 20 minutes of the distillation. This was distilled for about two hours and the total yelled of hydrosol was 600ml from 3.4 litres water and approx 300 gm plant material. After emptying and cleaning the still I completed the day with a batch of "attar of roses' (Pelargonium spp.). I had less of this plant-about 200gm of stripped leaves (number 3 in the picture below). This was the best aroma of the two rose scented, with a beautiful softness very much like the genuine Rose Otto oil. The yield was the best as well with 800 ml gorgeous hydrosol from 250 gm plant material and 3.4 litres water. perhaps as it was less dense in the still it was possible for more steam to be created. I will be planting more of this cultivar for sure!
Some information on geranium plants.
"Geranium" oil and hydrosol is actually distilled from plants from the Pelargonium genera NOT the geranium genera. However both are from the Geraniaceae family. There are many varieties and cultivars and oil sold is often mislabelled. The ones most highly prized are the ones with have aromatic leaves. The most common types of geranium oil sold is either "geranium' (Pelargonium graveolans) or 'rose scented geranium" (usually Pelargonium graveolans). Sometimes they may be labelled P. capitum. (However to add some confusion there is actually a rare essential oil distilled from Geranium macrorrhizum, which gives us 'zadvretz' oil.) I have also purchased a co distillation of an essential oil which is rose petals co distilled with Pelargonium spp., giving rise to a delightful aromatic blend.
Most pelargoniums grown for essential oil distillation are grown in Egypt, South Africa, Bourbon, China and India. There are significant chemical and quality variations between locations which is well documented.
The essential oil is primarily in the leaf, rather than the flower and has a distinctive aroma depending n the composition. The essential oil is produced by steam distillation. A solvent based leaf extract is also produced (geranium leaf absolute) which is used in fine perfumery giving fresh green notes to a blend. P. graveolans can smell quite sharp and almost bitter, compared with the rose scented which is exactly as the name says. I have also smelt peppermint leaf and chocolate leave geranium plants.
Early explores took cuttings of pelargonium back from South Africa to England and Europe. Very few scented pelargoniums are actually true species, rather they are hybrids created by selected breeding or by a chance insect pollination.
- "Lemon Scented' P. crispum -there are several varieties of P. crispum. One (major) is larger than the other. The leaves are small and crispy as you can see in my photo. It gets woody very quickly. Small flowers. Mine has a very strong and pleasant lemon aroma.
- "Rose scented" P. graveolans-there are several versions of this plant. The 'Reunion rose' is a special variety grown on the reunion Islands for essential oil production. My plant has a distinctive rose aroma, with a slight sharpness. (leaf 2 in image)
- "Attar of Roses" is a cultivar and has small single lavender flower. One of its ancestors is P. capitum. My plant had a soft sweet rose aroma.
Sources and Further Reading
- Geraniums The Complete Encyclopaedia, Faye Brawner (2003) ISBN 0-7643-1738-5 Schiffer Publishing
- The Complete Guide to Aromatherapy, 3rd Edition, Vol 1-Foundations and Materia Medica, Salvatore Battaglia, (2018), Black Pepper Publishing, ISBN 978-0-6482606-0-8
- Aromatherapy Science A guide for healthcare professionals, Maria Lis-Balchin (2006), Pharamaceutical Press, ISBN 0 85369 578 4
Posted: Tuesday 4 January 2022