Extracting compounds such as THC and CBD from marijuana enables users to benefit from a high concentration of a specific cannabinoid. For example, proper THC extraction allows you to create cannabis concentrates, which could have a THC level of over 90%! Extraction via alcohol is one of the most common methods.
When it is performed correctly, it is a safe form of extraction, BUT you must choose the right type of alcohol. Do NOT select denatured alcohol because it contains harmful ingredients which make it unfit for human consumption.
What is Rubbing Alcohol?
There are several types of alcohol, and not all of them are suitable for drinking! The alcohol we drink in the form of beer, wine, or spirits, is ethyl alcohol produced by yeast. In winemaking, for example, the yeast consumes the sugar in grape juice and creates alcohol.
Ethanol is the same kind of alcohol found in whiskey and is also used as car fuel. It is different from the stuff you drink because it has been distilled to the point where it is almost entirely alcohol. The denatured alcohol you find at the drug store is also ethanol, but it is poisoned to prevent people from drinking it. Food grade ethanol is a popular solvent for THC and CBD extraction and is still used by several big sellers.
Rubbing alcohol is the term used to describe either ethanol-based liquids or isopropyl alcohol. While denatured alcohol is classified as a methylated spirit, rubbing alcohol is a surgical spirit. It is widely used in medicine as a topical application. It is often a form of denatured alcohol made from a unique solution of 70% ethanol or isopropyl alcohol in concentrated form.
The term ‘rubbing alcohol’ is actually a generic term to describe ethyl or isopropyl-based products with similar qualities. In the UK, rubbing alcohol is often referred to as ‘surgical spirit.’ In North America, methyl salicylate is added to rubbing alcohol, which is commonly known as wintergreen oil. In Canada and the United States, manufacturers are allowed to use their own standards of formulation, as long as the isopropyl or ethanol alcohol content is labeled and ranges from 70% to 99%.
Both ethanol (chemical formula C2H5OH [also written as C2H5OH]) and isopropyl alcohol (chemical formula C3H8O) are used as disinfectants. However, while ethanol has no lasting short-term effects when consumed, isopropyl alcohol gets converted into acetone in the liver; which means it is incredibly toxic.
The term ‘rubbing alcohol’ was first used during the prohibition era in the 1920s. It was used as an ointment in massages and was rubbed into the skin. As it was an age where the consumption of alcoholic beverages was illegal, it was necessary to distinguish the type of alcohol one drank from the kind used in medicine.
Is it Safe to Use Rubbing Alcohol for THC Extraction?
There is some confusion over whether rubbing alcohol is even safe for use as a solvent for THC extraction. While it is true that isopropyl rubbing alcohol and denatured alcohol share similarities, their chemical structures, toxicity, and means of production are different.
Neither version is suitable for human consumption. Indeed, only food grade ethanol or ethyl alcohol can be safely consumed. Isopropyl alcohol is the name of a substance, whereas denatured alcohol is a commercial product which can contain several materials including ethanol and isopropyl alcohol. It also includes denaturants which make it unsafe for consumption.
However, there are different types of rubbing alcohol. In the United States, in accordance with ATF rules, all preparations classified as rubbing alcohol must have toxic additives to limit human consumption and prevent alcohol abuse. These forms of rubbing alcohol must have between 87.5% and 91% of absolute ethyl alcohol. The rest of the solution contains denaturants, water, and perfume oils.
There are also specific isopropyl rubbing alcohols with anywhere between 50% and 99% isopropyl alcohol. Therefore, if you are going to use rubbing alcohol for THC extraction, you will ideally choose one with up to 99% isopropyl alcohol.
Although you CAN use isopropyl based rubbing alcohol to extract THC or other cannabinoids from marijuana, it is safer to use ethanol. If you plan to use isopropyl alcohol for whatever reason, the process is known as Quick Wash Isopropyl (QWISO).
How to Perform QWISO THC Extraction
Isopropyl extraction involves stripping the trichomes from marijuana flowers to create potent hash oil. If you want to use this method of extraction, you’ll need the following equipment:
- A metal screen or filter (you can use a permanent coffee filter)
- A clean glass bowl
- Paper coffee filters
- A glass pot (a coffee pot works well)
- A glass mason jar
- A plastic storage container
- A large sieve; we recommend a large and a small sieve if you are using more than 10 grams of bud
- Cutting utensils
- A fan
- An oven
- 100-200ml of isopropyl alcohol
- At least 10 grams of bud
- A razor blade to gather the extract
Preparing for the Extraction Process
When it comes to THC extraction using isopropyl alcohol, preparation is crucial and begins several hours before you attempt the process. Make sure every container you plan on using is extremely clean and dry. Next, grind up your buds into a small jar and put it, and the alcohol, in a freezer for a few hours (you can even do this overnight) to ensure they are as cold as possible. Isopropyl alcohol’s freezing point is approximately -128.2 degrees Fahrenheit, so there is nothing to worry about!
You need to freeze the bud because its trichomes fall off far more efficiently at very low temperatures. You can attempt the extraction process without freezing, but it will result in a far smaller amount of THC.
Final preparation steps include placing a coffee filter into your jar to create a type of bag. If you plan on extracting THC from a large amount of bud, cover the entire surface area of your large sieve with filters and place the smaller strainer on top.
Extracting THC Using Isopropyl Alcohol
Pour all of the alcohol into the jar containing the weed. Make sure the ground buds are entirely submerged in the alcohol. Close the lid and tighten it securely. Shake the jar vigorously for 30 seconds. Don’t shake the jar for too long because you could extract too much chlorophyll, which will leave a bitter taste.
Next, pour everything through a sieve and filter the contents in a jar. The filtering process could take up to an hour, so be patient! If you have any alcohol left over, pour it into the jar to ensure no leftover trichomes are remaining. Filter this additional solution.
The process works because the cannabinoids in the weed dissolve in the alcohol. The sieve filters the plant material, while the coffee filter refines the liquid by removing tiny parts of the remaining plant. As all of the cannabinoids have been dissolved, they are now in liquid form. The coffee filter enables liquid to pass through but prevents solid particles from doing so.
Once the filtering process has been completed, you are left with a jar containing a fairly clear liquid with a hint of green. Now, your precious THC is contained in the liquid, which means we must remove the alcohol.
Pour the contents of the jar into a container with a flat surface. If you have a fan, you can set it to blow into your liquid at its lowest setting. Please note that the alcohol must be stored in a well-ventilated area because you are evaporating a toxic and flammable substance. It could take up to 24 hours for the evaporation process to be completed.
The evaporation process is only completed when you see no traces of liquid on the flat surface. Get your razor blade and a clean mason jar, and gather the solid substance. A toothpick is a handy item to have as it can remove pieces of material that get stuck to the razor blade.
Don’t be dismayed when you see such a small amount of material. It should contain at least 70% THC (depending on the strain), and a little goes a VERY long way.
Final Thoughts on Using Rubbing Alcohol to Extract THC From Weed
The answer to the title question is ‘yes,’ but with a fair number of caveats. Firstly, you should NEVER use denatured alcohol as it is designed to be poisonous. If you are going to use rubbing alcohol as your solvent of choice, it must be isopropyl-based; ideally up to 99%.
There is a significant amount of confusion when it comes to distinguishing between different types of alcohol. Ethyl, or grain, alcohol is used in the recreational beverages that millions of people enjoy. Manufacturers denature ethyl alcohol by including poisonous substances which render the solution undrinkable.
Isopropyl alcohol, on the other hand, is already unfit for human consumption. Ingesting it can cause intestinal bleeding, vomiting, and occasionally, death. It is less toxic than denatured alcohol but is still poisonous to humans.
Therefore, if you insist on using isopropyl alcohol for THC extraction, extreme caution is advised. You need to ensure that all of the alcohol has been evaporated before using the leftover cannabis concentrate. It is a common solvent in DIY extraction, but we would recommend using food grade ethanol instead.
Once again, you need the ethanol to completely evaporate before using the concentrate. However, if you don’t remove 100% of the ethanol, and consume marijuana, you should not feel too many ill effects since ethanol is safe for human consumption. In fact, it is often used as an additive and food preservative.