BlogHow to make concentrated cannabis oil (and not blow yourself up)
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How to make concentrated cannabis oil (and not blow yourself up)


Making cannabis oil is not as hard as one would think. Once you have the ingredients and a few things - that can usually be found around the house - you are all set to go.

"Clear your schedule for the next eight hours..."

cannabis oil first phase

Making cannabis oil with isopropanol: the basics

There are various ways to make concentrated cannabis oil but I find the following to be the easiest to do in a home.

The two ingredients are ground dried (or decarboxylated) cannabis buds and 99.9% isopropanol.

cannabis oil flasks


I grew the cannabis myself in my greenhouse and I bought the isopropanol online from Amazon. Ideally, I would have gotten pharmaceutical grade isopropanol (gamma irradiated and filtered) but that didn’t seem to be an option to ship to my locality.

I bought cosmetic grade isopropanol (for nail shops) - the 99.9% alcohol will evaporate - theoretically, the remaining 0.1% should be water. According to this Wikipedia article on isopropanol (which I highly recommended reading if you intend to work with isopropanol) it “evaporates quickly, leaves nearly zero oil traces, compared to ethanol, and is relatively non-toxic, compared to alternative solvents.”

The residue of evaporated isopropanol may be “relatively non-toxic” but ingestion of the liquid or inhalation of the fumes is toxic. It is also highly flammable. Take precautions as described throughout this article.

Safest source (but most expensive) for isopropanol will be your local pharmacy - in case they ask, a legitimate use for isopropanol is to clean the inside of a computer, the solvent cleans and evaporates without leaving a residue on your motherboard. I’m a terrible liar - so went for the online option instead.

You need a ratio of 100 grams of ground dried cannabis buds to one litre of 99.9% isopropanol. For example, for a 90-day course of cannabis oil - as per Rick Simpson’s directions - you will need 500 grams of dried cannabis and five litres of isopropanol.

My experiment was for educational purposes rather than cancer treatment so I used up some leftover buds and trim. It amounted to just under 35 grams of cannabis - which is about an ounce and a quarter. Therefore, I needed 350ml of alcohol.

The process took me a couple of hours. You need more time for the isopropanol to evaporate (at least 24 hours).


  • Grinder
  • Scales
  • Glass measuring jug
  • Glass mason jar (with a sealable lid)
  • Tall open glass jar (pint glass or a vase is good)
  • Nylon stocking
  • Elastic band
  • Rubber gloves
  • Large glass bowl

Ingredients for making cannabis oil with isopropanol

  • Dried cannabis flowers (or trim)
  • 99.9% isopropanol

The ratio is 100 grams of cannabis per one litre of isopropanol


IMPORTANT NOTE #1 - where you live processing cannabis into concentrated oil is most likely illegal. Be aware of the local laws before proceeding.

IMPORTANT NOTE #2 - do this outdoors or under a strong extraction fan (that extracts the air outside the building) on full blast with all windows open! Failure to do so - will at best get you feeling very sick and at worst start a fire.

  1. Grind the cannabis and put into a large glass bowl.
  2. Weigh cannabis and figure out the ratio to isopropanol (100 grams per litre).
  3. Measure the isopropanol in a glass measuring jug.
glass measuring bowl

Make sure the area is well ventilated and don’t inhale the fumes.

4. Put cannabis in the mason jar and add isopropanol. Close the jar and gently shake. You need to make sure all the plant material is covered in isopropanol.

closed jar with weed


5 - Leave for 30 minutes to let the solvent (isopropanol) strip the essential oils from the cannabis.

6 - Cut the stocking so that you have at least 2 layers (I had four layers) and put over the top of the open glass jar to act as a strainer (see photo). Use the elastic band to hold it in place.

scissors, stockings


7 - Put on your rubber gloves and pour/spoon the contents of the mason jar into the opening of the stocking. Pour in a little more isopropanol into the mason jar and give it a swish around to get the remaining leftovers. Leave the stocking to strain the plant material from the isopropanol and rinse the mason jar with water.

stockings filled with weed


8 - Move the elastic band so that it closes up the opening of the stocking and wearing your rubber gloves gently squeeze out the cannabinoid-rich isopropanol from the stocking into the open-topped jar. Once you have got all the liquid out you can dispose of the stocking and plant material.

strain weed

9 - Pour the contents of the jar into the large glass bowl. Again, rinse out the leftovers with a little isopropanol and the jar with water. The area must be well ventilated and don’t inhale the evaporating isopropanol.

bowl with residue


10 - Put the bowl - with your green liquid - either outdoors or under an extraction fan (kitchen fan is great, but make sure there are no naked flames).

11 - Wait for the isopropanol to completely evaporate - this can take a day or two depending on the ambient temperature and volume of liquid you are using. The process can be sped up to a few hours by using a “bain Marie” to gently heat the mixture (bowl inside a pan of boiling water) - the boiling point of isopropanol is 80.37°C. Do not do this if you don’t have an extractor fan sucking the alcohol vapour outside of the building (you will poison yourself). Also, do not attempt this with a naked flame as the heat source (you will blow up your kitchen).


au bain Marie

12 - You will be left with a very sticky dark green/black tar-like oil which - depending on the source material - will be very high in THC and other cannabinoids.

cannabis concentrate

How to consume concentrated cannabis oil?

What you do next depends on what you intend to do with the oil.

If you want to make an oil for taking drops you can dilute it in olive oil and put in a dropper bottle. Heating the oil gently in a “Bain Marie” will make it easier to work with.

If you are going to ingest the oil be aware it is extremely potent. Clear your schedule for the next eight hours and try a tiny amount (half a grain of rice size) to check the dosage. Wait a few hours before taking any more. For treating cancer and other serious conditions you can increase the dose daily until you are taking the correct dosage - do more research on what that dosage should be. The dosage information on Rick Simpson’s website is a good place to start.

If you want to use the oil for recreational use then you can dab or vape it as it is - use in moderation as it is incredibly potent.

It’s mega sticky so some silicone dabbing kit is handy to get hold of Dr Dabber has a nice range of tools. I use their silicon Honey Mat to avoid getting sticky cannabis oil all over my coffee table.

concentrate Dr Dabber storage ball

I store the results of my “experiment” in their silicon storage ball. It’s also very useful to have a dabbing tool handy - not just for transferring your goo to your vape or dab rig but to scrape up any drips from your silicon mat.


concentrate ready for Puffco action

Another way to use your freshly made cannabis oil is with a vape pen. I found that the PuffCo Plus vape pen was particularly well suited to vaping cannabis oil as the built-in dab tool - “the dart” - helped keep the pen relatively clean. Though I still manage to get that sticky oil everywhere!

Bill Griffin, Author of Easy Organic Weed

All images: copyright Bill Griffin

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