Introduction: How to Make Aromas or Perfumes With a Soxhlet Extractor and Reflux.

About: I am a part-time hobbyists biotechnologist with a photonics background. I also have a YouTube channel too. I work full time now.

Hello, I really like making my own scent with spices, herbs, etc. I have made Cocoa aroma perfume in ethanol 70 percent, Ginger-Cinnamon in 70 percent ethanol, Methyl salicylate and Menthol from pain liquid gel in 70 percent ethanol and Storax resin in 70 percent ethanol.

Warning: Ethanol and other alcohols are flammable and toxic (external uses only). Distillation without an Oil bath can lead to cracks in the flask potentially causing an explosion. Sulfuric acid 98% is an extremely powerful acid wear thick Nitrile gloves (Min) to protect yourself from skin contact. Acid burns, especially at this concentration, really hurt. Making ester often requires concentrated organic acid which is corrosive and toxic. Wear a face shield. For the esters, it should be done in a well-ventilated area. For the reflux and the prep of the herbal soxhlet extraction always check on it 10-15 minutes and do not leave it on for long periods of time (Max 6 hours a day).

Most ethanol you can buy 70 percent is pretty good however in some cases when you make ester (Ethyl acetate, Ethyl formate, etc) you require Ultra pure ethanol. 70% ethanol can be salted out easily.

Here is a video on how to convert 70 percent ethanol into 95 percent min ethanol by salting out.

Here another Video from Troll face on salting out yes for many soluble alcohols (Methyl, Ethyl, and Isopropyl) as primary alc you can use this method for very pure alcohol.

How to use a Soxhlet extractor. Protocol video.

I use my Soxhlet extractor for extracting aromas in ethanol.

I place freshly chopped aromas in ethanol in the boiling flask as a reflux type material. This concentrates the aroma in the ethanol.

For some aroma like Storax and Pine resin in 70 percent may be too strong alone and may have to be diluted with 70-95 percent ethanol ( Half of the Pine or Storax or One-fourth of it) or Lower. Really strong aromas like Thyme may also need to be diluted.

An alternative is to take 70 percent ethanol and use Molecular Sieves to remove water from the ethanol-making it near 94-95 percent ethanol. Here a video on how to do that.

Since they add 4-5 percent inhibitors ( to make it taste bad). This means you can only get max 94-95 percent ethanol out of this way.

Another video on Lab grade vs Chinese Molecular Sieves. I say if you get them cheaply just use 20 percent more.

Step 1: Attempting to Distill Drain Cleaner Sulfuric Acid for Making 98 Percent Sulfuric Acid. (OPTIONAL THO).

I do not recommend doing this since it much much safer to buy Sulfuric acid 98 percent Online like E-bay, etc.

If you can get hold of Normally 96 percent Sulfuric acid Drain Cleaner with Inhibitor and you have the time and patience then you can add to 250 ml of Drain cleaner Acid about 15-20 ml very very Slowly 30-35 percent Hydrogen peroxide. Then boil it.

Both Distilling Sulfuric acid and boiling it to 327 degrees C with Hydrogen peroxide (H202) is extremely dangerous. Glass boiling chips in a large amount equal mass of the volume (Must be ADDED). It produces some Sulfuric acid vapors which are class 1 cancer-causing and very corrosive and toxic by inhalation, skin contact.

Indeed this can work but the H202 has be added to the Sulfuric acid (Not the OTHER WAY AROUND) if it is done incorrectly it could explode!!! It forms Caro's Acid (Weak version) that attacks the Corrosion inhibitors. Caro's acid is H2SO5. It a very potent Oxidizing acid tho!!

The Hydrogen peroxide concentrated should be in the fridge or ice cold. The lower the temperature the less energy it will release. Boiling Sulfuric acid concentrate is a HUGE DIFFERENCE than the normal 20 degrees C!!!

Distilling to 337 with a controlled heating mantle in a well-ventilated area is a bit better and may give a better purity (95-98) percent sulfuric acid. Here two videos on it.

Step 2: Steps for Soxhlet Extracting Ethanol With Material.

I strongly recommend (You MUST) have some type of glass or other boiling chips when working with ethanol. Heating even a boiling flask halfway with ethanol (due to it volatile properties it must have proper boiling chips).I prefer expensive glass types. Even if 500 grams cost 50 dollars it is well Worth it in the long run.

Eventually, I will show how to make with concentrated Sulfuric acid, Alcohol (near 95 percent) and organic acid some simple esters. Calcium carbonate boiling chips do not work due to the acid (Sulfuric) and dissolve and create a big mess and ruins your results.

For many of the samples, I pour in 250-450 ml of 70 percent ethanol with a vary of grams of chemicals.

1. Coffee, 2. Coffee-Cinnamon. 3. Cocoa. 4. Mint. 5. Allspice. 6.Spearmint. 7. Nutmeg (96% ethanol (Salting out required). 8. Storax in 70 percent ethanol. etc. I have also tried ethanol with Pepper (black) and Paprika and Dill aroma.

I place x amount of one spice with y amount of another spice. It depends on how strong you want to make it tho. One I had 15 g of chopped up ginger and 7.5 g of cinnamon for 300 ml of 70% ethanol.

I will by May I will be getting Menthol crystals 28 grams so I will make a mint like substance with boiling ethanol 70%. Right now I am Soxhlet extracting 4 g of Tyme. It produces Thymol Aroma 0.25 g to 1 g per 450 ml (70% ethanol).

Step 3: How to Set Up a Soxhlet Extractor (My Method Way) for Aromas Includes Density Tests Link and Video for Ethanol.

Some calculations of Chemical that you are extracting roughly is required. Every chemical extract will be different so you will have do your own Research!!

Some info on filtering with gravity or a Büchner funnel method.

Here a video on how to calculate the density of ethanol (Mine was 94-95 percent ethanol) Salting out method.

With a graduated cylinder take your salted out ethanol and put 5 ml into it. Weigh using a digital scale and taring the sample. Thus you can get the Density (Mass divided by volume).

My graduated cylinder has a volume error of 1 percent. 5 ml *0.01 = 4.95 ml Lowest. Highest error 5.05 ml.

Density of ethanol = 0.7893 g per cm3 or ml at 20 degrees C.

The range of min and max ethanol (95 percent) grams is 3.908 g to 3.986g for 100 percent ethanol.

The range of min and max 95% ethanol is 3.712 g to 3.79 g ethanol weighed out.

There are endless combos of aromas so here a general info.

Say I want 50 g of Pine Resin which contains Pine Oils 2 percent. Since Abietic acid is 90 percent or so.

50 g in 450 ml ethanol at 70 percent. 50 grams Pine Resin *0.02 = 1 g Oil*0.90 = 900 mg Pine Resin per 450 ml of 70 percent ethanol.

In a Two 1 L flask ( My Soxhlet extractor max volume extraction is only 500 ml). Put in your desired chemical (solvent). I am using 70 percent ethanol (for most materials I have used it is sufficient). Then put in your desired powder or tree leaves (Mint, Cedar, and Thyme are good examples).

On a hot plate add a pan and put in Vegetable Oil. I found any vegetable Oil will do as long as it can tolerate past 120-200 degrees C. To the flask add a thermometer stopper and thermometer to one of the joints of the flat flask (I prefer that) and add the boiling chips (glass are preferable) but others will do to the flask maybe 10-15 grams of them.

Clamp the boiling flask securely. Add the pyrethrum cup (Soxhlet extractor device) with proper clamps. The pump should be attached to the top highest port of the condenser and water flowing through the tube will flow back into the pump.

Do remember to keep the tubes from dropping and getting to close to the heat source. This can damage the tubing and the pump (break down of the tube releases material and permanently clogs the pump destroying it).

Step 4: Making the Esters.

As long as you have a reflux column and flat flask and you can make it between 100-150 degrees C then it very possible to make different esters.

Check this Link to find out many different types of Esters that are possible.

As the Protocol, I am following Red Nile Video.

Here How to make grape ester aroma.

How to make Methyl Salicylate is here as well.

If you are going to use a Reflux column you need a drying tube fit in between with Molecular Sieves. The acid will not evaporate until 330 degrees C. So it must be without water!! Dehydrating agents like Calcium Chloride without water may be used instead. I am using ethanol to make ethanol 99 percent by drying it after salting out. If water is added the ethyl salicylate will convert back into ethanol and salicylic acid!!

For all these steps I don't mind leftover ethanol, etc so some Impurities for my use is fine. I will not do methyl or ethyl Salicylicate due to the high temp required but I may do ethyl formate and ethyl acetate.

I have made different ester in the lab but for many of the materials I do not have access to formic acid 98 percent and 30 ml on e-bay could easily cost 80-100 dollars CAN. So I will show how but I have not done any esters. It still shows how it can be done for aromas, etc.

Step 5: Results of Some of the Materials.

Both the Soxhlet extractor and the Aroma perfume from reflux column distillation method made different types of aromas.

I found a glass bowl and a towel (Small one) I can add 100 ml of aroma and it last for 5-7 days long. It truly depends on humidity and vapor pressure of your apartment or house tho.

Normally for a lot of spices and aromas 70 percent ethanol is fine. However, if you want to extract for example painkiller gel you may need around 95 percent ethanol. You can buy it or salt out 70 percent ethanol and normally a bit of salt does not affect the final product.

Emulsions and foam can occur with trying to extract pain gel creams. So this method can be DIFFICULT. I haven't had a lot of luck.

Step 6: Final Thoughts.

Both Soxhlet and Reflux type extractions of Herbs and spices are very good and give amazing different and unique aromas. They may be used as Air fresheners or perfume if you want too. An oil bath and a temp around 80-100 degrees C are required too. Also, a hot plate and stirrer may also be recommended but not necessary (it Optional).

For the esters, you must reflux and have Ultra pure chemicals 98 percent alcohol and acid and 98 percent sulfuric acid. For my application, I don't need to make them but I have shown how to in this Instructable tho. It also must be water free too.

Thank you for Reading this Instructable.


I may post comments on later projects like Frankincense Resin, Menthol Mentha Crystals or other types of aromas I think of.