You see e-cigarettes everywhere you go these days. And if you live in a green state, you also see cartridges pre-filled with THC, which are more and more popular due to their discretion and convenience.

But what if you don’t live in a state with legal marijuana? And what if you do live in a legal state, but don’t want to pay premium prices for your THC cartridges?

Here’s the good news: You can do it yourself, and you won’t go broke doing it. While homemade THC oil might not quite measure up to the premium cartridges available in dispensaries, it can still get the job done.

Here’s what you’ll need to make your own THC e-juice

If possible, use cannabis concentrates to make THC oil for your cartridges. (It saves a step.) If you don’t have access to concentrates, you can use flower and trim.

• 7 grams or more of flower (more if lower grade) or 1 gram of high-grade cannabis concentrate
• 2 glass jars (Mason jars are ideal); freeze for 2 hours before the process begins
• Cheesecloth or coffee filters for straining
• Baking sheet or Pyrex bowl
• Freezer
• Oven
• Stovetop
• Pot for boiling
• Precise thermometer
• Aluminum foil
• Baking sheet
• Dropper bottles (5 ml is a good size; those cobalt-blue ones work well)
• PEG400 or a mix of polyethylene glycol (PEG), propylene glycol (PG) and vegetable glycerin (VG)
• Everclear (the booze, not the band), or another high-proof alcohol. (Avoid using rubbing alcohol.)

Decarb your weed

Decarbing takes place when you smoke marijuana. But vaporization doesn’t always get hot enough to do the trick, so this step is important to make sure the THC is activated.

The decarboxylation process won’t be necessary if you’re using concentrates to make your e-juice, so that can save you a little time. With flower and trim, you want to decry so that any THC acid (THCA) is converted into psychoactive THC. THCA has health benefits but won’t get you high.

1. Grind your marijuana finely into a baking sheet covered with aluminum foil.
2. Heat the ground-up cannabis in the oven at 225 to 240 degrees Fahrenheit for 15 to 30 minutes.

Extract the THC with alcohol

1. Remove one of the glass jars from the freezer
2. Take the decarboxylated marijuana and put it into the jar
3. Pour in enough Everclear or other high-proof alcohol so that the cannabis is completely submerged. Gently swish the mixture back and forth, not up and down
4. Return the jar to the freezer for a minute
5. Get the second jar. Put the cheesecloth at the top and pour the mixture through. Squeeze every drop out of the cheesecloth into the jar

Evaporate any remaining alcohol

A water bath is the final step before the e-juice mix is introduced. A water bath is used to keep any flames separated from the flammable alcohol.

1. Fill the pot with about 4 inches of water. Place the mason jar filled with infused alcohol in the water for about an hour. A water temperature of 160 degrees Fahrenheit is ideal if you have a thermometer handy
2. When there’s no alcohol left, add your PEG, food-grade vegetable glycerin, or propylene glycol. You can experiment with the amount to suit your preferences. More cutting agent will result in bigger clouds when you vape. But remember, that means less THC per puff. If your main objective is getting high, not blowing clouds, use just enough cutting agent to loosen the consistency to fill cartridges.

If you simply don’t want to heat your marijuana-infused alcohol, an alternative method is to let the alcohol evaporate naturally. The downside of this process is that it takes 10-14 days.

About one milliliter of glycol is normally enough to make a gram of concentrate into a liquid suitable for cartridges or tanks for e-cig vaping. To avoid spillage, use a syringe to transfer the e-juice to cartridges or tanks.

Remember, one way you can usually get away with getting high in public is vaping from a box mod typically used with nicotine e-juice. Some stealth smokers even add flavoring to help mask the marijuana smell.

The e-juice you make has a shelf life of a least six months to a year in the dark at room temperature.