Using steam distillation, essential oils can be extracted from plant materials like herbs and spices. The process involves boiling biomass in water to produce steam, which carries the essential oils into a condenser where they separate from the water. While Paracelsus coined the term "essential oils" centuries ago, the underlying science of vapor pressure differences enables effective distillation using modern laboratory glassware like a biomass flask, condenser, separation funnel and hot plate. Following steps to assemble the apparatus, add materials, and operate it safely can produce valuable essential oils.

1. Using Steam Distillation to Produce Essential Oils
Andrew Collins

2. Introduction
The Renaissance physician Paracelsus (1493-1541) did not invent steam distillation,
but rather the modern term used for the volatile oils of plants—essential oils, directly
recalls his alchemical theory of quinta essentia (literally fifth element).
For Paracelsus the process of distillation involved harnessing the innate powers of
fire and flame to separate and purify the essential characteristics from crude matter.
Today the theory behind this common laboratory procedure is far less romantic or
poetic, involving directly quantifiable differences in vapor pressure and Raoult's Law.
Theories aside, Paracelsus was an expert distiller and the alembics and retorts (see
examples on title page) he used to produce essential oils are similar to the laboratory
equipment used around the world today. Therefore these instructions will make use
of modern laboratory equipment.
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important information.
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3. Required Glassware
Biomass Flask
x3
Addition Funnel Condenser Separation Round-Bottom
Funnel Flask
Stopper Clainsen Adapter Still Head Distillation
Adapter
2

4. Additional Required Equipment
Water Tub Tubing
Hot Plate Water Pump
3

5. Apparatus Assembly
Stopper
Biomass Flask
Still Head
Condenser
Addition
Funnel
Distillation
Adapter
Clainsen
Adapter
Tubing
Separation
Round- Funnel
Bottom
Flask
Water
Hot Plate Water Pump
Tub
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6. Necessary Materials
Water
Steam distillation requires boiling water to produce steam.
Ice
To operate effectively the condenser requires cold water.
Biomass
Choose plant material which is suitable for steam distillation.
The following represents a mere fragment of all possibilities:
caraway, cinnamon, clove, cumin, rosemary, peppermint,
spearmint, and lavender.
To prevent personal injury
Persian physician Avicenna
avoid steam discharges
(c. 980 - 1037) invented
! from the apparatus and
avoid operating around
? steam distillation in the
eleventh century.
children or pets.
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7. Apparatus Preparation
1. Check for loose
connections between
glassware. H2O
2. Add water to Round-
Biomass
Bottom Flask,
Addition Funnel, and
Water Tub.
3. Load biomass into
Biomass Flask.
4. Make sure Water Pump
is operating and
condenser water is H2O
flowing.
5. Add ice to Water Tub.
H2O
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8. Apparatus Operation
1. Turn on Hot Plate.
2. Confirm steam is
being generated.
3. Check for steam H2O
leaking out of
glassware.
Biomass
4. Verify Water Pump is
operating and
condenser water is
flowing.
5. Add ice to Water Tub
as necessary.
EO
6. Transfer water from
Addition Funnel to H2O
Round-Bottom Flask
as necessary.
7. Watch essential oil H2O
begin to collect!
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9. Collecting Essential Oil
1. After 2-4 hours the steam distillation will
be finished.
2. Turn the Hot Plate off and let the Essential Oil
apparatus cool down. Remove the Lighter Than
Separation Funnel. Water
3. If essential oil which is heavier than water
is in the bottom of the separation funnel
Water
collect it by carefully turning the stopcock
and quickly closing the stopcock.
4. Drain away water collected in the Essential Oil
Separation Funnel. Heavier Than
5. If essential oil which is lighter than water Water
is in the top of the separation funnel
collect it.
It is important to open and Annual global production
close the stopcock quickly of spearmint oil is 1400
! and firmly, otherwise ? metric tons, 70% comes
essential oil may be lost. from the United States.
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10. Bibliography
Adams, Roger, John R. Johnson, and Charles F. Wilcox. Laboratory Experiments in
Organic Chemistry. New York: Macmillan, 1979. Print.
The Alchemy Web Site. Web. 10 May 2010. <http://www.alchemywebsite.com/>.
"Essential Oil." Wikipedia, the Free Encyclopedia. Web. 10 May 2010. <
http://en.wikipedia.org/wiki/Essential_oil>.
Fessenden, Ralph J., Joan S. Fessenden, and Patty Feist. Organic Laboratory
Techniques. Pacific Grove, CA: Brooks/Cole Thomson Learning, 2001. Print.
Harwood, Laurence M., Christopher J. Moody, and Jonathan M. Percy. Experimental
Organic Chemistry: Standard and Microscale. Oxford: Blackwell Science, 2008.
Print.
Pavia, Donald L. Introduction to Organic Laboratory Techniques: a Small Scale
Approach. Belmont, CA: Thomson Brooks/Cole, 2005. Print.
"Steam Distillation." Wikipedia, the Free Encyclopedia. Web. 10 May 2010. <
http://en.wikipedia.org/wiki/Steam_distillation>.
Teuscher, Eberhard, Ulrike Bauermann, and Monika Werner. Medicinal Spices: a
Handbook of Culinary Herbs, Spices, Spice Mixtures, and Their Essential Oils.
Stuttgart: Medpharm, 2006. Print.
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