Before we get into the details. Not all isopropyl alcohol is the same!
Some brands leave a residue behind. You can tell by burning off a small amount of the alcohol on a dish. If there is black smoke, or a residue left behind; then you know it's probably not a good idea to use for extracting your oil.
I have excellent luck with Alchemist brand 99.9% Technical Grade isopropyl alcohol
I am able to get this at my local hydroponics store cheaper than on Amazon, but 91% isopropyl is available everywhere. Often, 1 gallon of 91% is $10-$15.
This blog and video is only to demonstrate the effectiveness of hot vs cold extracting. Anytime when boiling alcohol is involved, explosions or fire can happen. If you use any of these methods, they are at your own risk. A few safety tips:
So, in other words. This website and myself are not responsible for people being irresponsible, and starting a fire, blowing up their house, or anything else. Don't try this at home, unless you really know what you are doing. All of this is at your own risk!!!
First, let's go over the fastest, most efficient, and best tasting way to go. This method can be dangerous. Hot alcohol produces flammable fumes, that will cause an explosion if not done properly.
This method is very quick, and the Full Spectrum Oil (FSO) is ready in about a couple of hours. Using a heat safe container, like a pyrex measuring cup. Fill it about 2/3 full of crushed up buds. Pour enough 99.9% alcohol over it to cover it by about 1 inch.
I microwave this in 15 second increments, and watch it closely. After 2 or 3 times, I see it just start to boil. To prevent fumes building up, turn off the microwave as soon as the boiling starts.
I let this sit for about 15-20 minutes, stirring occasionally. I heat it back to boiling before straining through a coffee filter. This makes it run through the filter fast. I pour more alcohol, and repeat the process. I soak the buds for a total of 3 times with hot alcohol, and this seems to get all of the oil off.
I did try this with 91%, and the taste/odor was awful. If there was such a thing as canned marijuana with sardines together, thats what the oil tasted like. So no more 91% for hot extracting. I thought maybe cold extracing might help.
I mashed up a bunch of CBD God Bud flowers up into 3 different glass jars, about 2/3 of the way up. After placing the lid on, they went into the freezer with the alcohol (separately) to get cold.
After they are cold enough, pour the alcohol to about 1 inch above the crushed flowers. Frozen alcohol will prevent the plant matter from soaking up the liquid, and provide a much cleaner tasting oil. I let this soak for 10 days, and I shook the jars twice a day.
After the 10 days were up, I strained it through a coffee filter. I added more frozen alcohol, and placed the jar back into the freezer while I waited for the other batch to finish straining. It took about an hour for the cold alcohol to strain. I repeated the process one more time, so the flowers were soaked 3 times. This was an attempt to get all of the oil off.
After boiling down the alcohol in a rice cooker, I was left with only 6 grams of oil.
I emptied the already extracted mashed up weed into a larger container, and filled with 99.9% isopropyl alcohol. This went into the microwave in 15 second increments until it just started to boil. (be careful not to cause an explosion doing that).
I let that set for a few minutes, and strained it out. I should have done one more wash, but I was not expecting the result. Another 6 grams of oil was extracted from that.
In the end, 99.9% is expensive. It does have the best extraction ability, with the cleanest taste.