top of page
Search

Laboratory QC Analysis for Essential oil content (Part 1)

  • Writer: Essential Stills
    Essential Stills
  • Feb 1, 2023
  • 2 min read

Updated: Feb 3, 2023

It is important to perform a QC check out any crop that you are going to distil for several reasons:

Firstly, this analysis will give you an idea of how much essential oil you should expect from your crop when it is distilled in commercial quantities. You can then ensure that you have enough aluminium flasks etc. available for the storage of the oil.

Secondly you can determine the correct harvesting time for optimum yield or aroma. Whilst the need to maximise the yield is obvious, the latter property is particularly important for certain essential oils, when a particular component with a highly desirable fragrance may only appear for a certain short period during the flowering cycle. Regular testing will enable the distiller to find the best time to harvest and this is likely to be a compromise between yield and aroma.

Thirdly it will enable the distiller to determine what agricultural areas are fine for planting, what areas will need e.g. added irrigation or fertilizer - and what areas should not be planted up at all for essential oil production.

Finally it enables the distiller to check out new varieties of crop or even check out new interesting plants to see what amount of essential oil is present and to see if it has any fragrance or flavouring potential.


The apparatus needed for QC testing of essential oil plants is as follows:


1. High quality CE Approved 2000 ml Heating Mantle with integral control panel

2. Pyrex 2000ml round bottom flask with 100mm flange opening.

3. Pyrex flange lid 100mm with central socket and angled side arm socket.

4. Pyrex stopper to seal off additional lid socket.

5. Pyrex custom-made Dean & Stark apparatus for essential oil separation and removal.

6. Pyrex custom-made ‘Graham’ condenser to fit the Dean & Stark apparatus.

7. Stainless steel clip to secure the two flanges together.

8. Heavy duty laboratory stand with10mm diameter rod.

9. Customised clamp with integral adjustable boss

10. Silicone grease for the ground glass joints.

11. Flexible tubing 6mm internal diameter for the condenser water.

12. Weighing scales accurate to 0.1g with a 500g capacity.


Assembly and operational instructions will appear in the next blog.



 
 
 

Recent Posts

See All
Vetiver Oil availability.

This beautiful essential oil is distilled from the roots of Vetiver grass ( vetiveria zizanoides) . These roots can penetrate to a depth...

 
 
 

Comments

More Information

 

 

What is it?

 

This Still comprises a boiling vessel with 6 elements at the base and a basket inside. A tall steam collection cone is fitted on top of the boiling vessel that carries a bend at its top that then joins onto an open horizontal 4” tube. This tube ends in a 90° bend that points downwards and this then joins on to the condenser with a 4” screw fitting.

 

​The condenser is a beautiful piece of kit with 36 narrow (8mm) thin-wall tubes fitted equidistantly within a 4” diameter stainless outer tube: there are 3 sets of baffles fixed at set intervals to make the water ‘chicane’ and maximise agitation and therefore improve its cooling capability. There is a cone at the base of the condenser to direct the distillate into the glass Florentine fitted directly underneath.​

 

How it Works:

 

The water boils, the dry steam goes through the plants in the basket collecting a bit of essential oil on the way and continues up the cone: at the top it turns 90°, goes through the top pipe and then heads down through the 36 pipes in the condenser. Since these pipes are surrounded by cold water, the steam then condenses into liquid and drops into the glass Florentine that is placed underneath. Here any oil present will separate and float to the surface, while the condensed water then trickles back to the boiling vessel via the S trap mounted a few inches up from its base.

 

​How to Operate:

 

Lift off cone/condenser unit and slide to one side and remove basket. Fill vessel with 40 - 50 litres of water, enough to cover the elements with say, an inch of water on top. Line basket with muslin and fill it with the material you want to distil e.g. lavender - and place it back inside the boiling vessel. Some form of lifting apparatus will be required e.g. simple sliding block and tackle. ​Slide cone/condenser unit back and lower onto boiling vessel, lock the clamps so that it all becomes one unit and turn on the heat. The Still has a wrap-around fabric insulation jacket made in two sections and one goes over the cone whilst the other goes around the boiling vessel. As the Still heats up, you can turn off some of the elements until a nice rolling boil is achieved. Make sure water is gently flowing through the condenser to keep it cold and the distillation continues until the oil layer in the Florentine stops growing. Then turn off heat and water and remove oil.

bottom of page