Safety first: read before you start
- Isopropyl alcohol fumes are highly flammable. Evaporate outdoors or with strong ventilation. No open flames, sparks, gas stoves, pilot lights or smoking anywhere nearby.
- Use a rice cooker with no exposed heating element, and never leave it unattended.
- Only move to the hot plate after ALL the solvent is gone. Use an electric hot plate, never a gas burner.
- Keep a fire extinguisher within reach the whole time.
- Make sure ALL the solvent is gone before consuming. Leftover isopropyl is not safe to eat.
- 21+ only. Follow your local laws. This page is general information, not medical advice. Talk to a doctor before using cannabis, especially if you take medications.
Equipment
- High-end cannabis, several different strains
- 99%+ isopropyl alcohol
- Glass or stainless bowls and a wooden or silicone spoon
- Freezer space to chill the solvent and plant material
- Coffee filters and a funnel or strainer
- Rice cooker (no exposed heating element)
- Separate single-burner electric hot plate (no open flame; a solid plate, not an exposed coil)
- Small stainless steel or heat-safe container for the hot plate
- Wireless (radio) probe thermometer
- Oral syringes (e.g. 1 mL or 3 mL)
- Nitrile gloves, eye protection
- Fire extinguisher
Wash many strains in cold 99%+ isopropyl
Use a mix of many different high-end strains. The wash is what decides the quality of the oil, so take your time here.
- Chill everything first. Put the isopropyl and the plant material in the freezer until they are very cold.
- Short, cold washes. Cover the plant material with the cold alcohol and stir or agitate for 30–60 seconds. Do a few quick washes rather than one long soak. Short and cold pulls the oil while leaving behind more chlorophyll and plant waxes.
- Strain through coffee filters. Pour each wash through coffee filters into a clean container. Combine the strained liquid.
Evaporate all the alcohol in a rice cooker
A rice cooker works well: it heats gently and holds a steady temperature. Do this outdoors or with strong ventilation, with no flames or sparks nearby, and stay with it the whole time.
- Fill the rice cooker no more than about two-thirds full, and add more liquid as it cooks down.
- Keep going until the alcohol has boiled off and only a thick, dark oil remains.
- Watch for the "pop." Once most of the alcohol has boiled off, the temperature rises and the rice cooker pops or clicks over to Warm. That's your cue to move the oil to the separate hot plate for the 235–240°F decarb.
Decarb on a separate hot plate at 235–240°F max
Decarboxylation activates the oil. Once the rice cooker has finished and the solvent is fully gone, move the oil into a small stainless steel or heat-safe container and set it on a separate single-burner electric hot plate.
- Keep it at 235–240°F max. Never go above 240°F.
- Check the temperature with a wireless (radio) probe thermometer so you can monitor from a safe, ventilated spot.
- Small bubbles will form as it decarbs. Watch closely. It is done when the bubbles stop.
Collect into oral syringes while warm
While the oil is still warm and runny, draw it up into oral syringes. It thickens as it cools, which makes it hard to pull up later.
Store it cool, dark and airtight
Cap the syringes and keep them somewhere cool and dark, in an airtight container, out of reach of children and pets. Label them clearly.
Dosing: start tiny, go low and slow
- Start with a tiny amount, about the size of a grain of rice.
- Wait before taking more. Effects of eaten cannabis can take a long time to show up, so wait several hours rather than re-dosing early.
- Increase slowly over days only if you need to. Don't drive or operate machinery.
RSO FAQ
Why use 99% isopropyl alcohol?
99%+ isopropyl has very little water, so it pulls the oil out quickly and evaporates cleanly. Kept very cold and used in short 30–60 second washes, it leaves behind more chlorophyll and plant waxes.
Why use a rice cooker to evaporate the alcohol?
A rice cooker heats gently and holds a steady temperature, with no open flame. Use one with no exposed heating element, work outdoors or with strong ventilation, and never leave it unattended.
How do I know the alcohol is gone?
Once most of the alcohol has boiled off, the temperature rises and the rice cooker pops or clicks over to Warm. Only a thick, dark oil should remain. Make sure all the solvent is gone before moving to the hot plate or consuming it.
What temperature should I decarb RSO at?
Decarb on a separate electric hot plate at 235–240°F max, and never above 240°F. Watch a probe thermometer and turn the hot plate down or off if it climbs. It is done when the small bubbles stop.
How should I store RSO?
Draw it into oral syringes while it is still warm, cap them, label them clearly and keep them in an airtight container somewhere cool and dark, out of reach of children and pets.
How much RSO should I start with?
Start with a tiny amount, about the size of a grain of rice, and wait several hours before taking more. Increase slowly over days only if you need to. This is general information, not medical advice.
General information for adults 21+. Not medical advice. Follow the laws where you live.