RSO Never Boiled

Hi folks,

This is my first post and my first attempt at making RSO using the QWISO method - but I'm not certain it worked properly.

I used 1oz of Indica (decarbed ahead of time) and 500ml of 99% ISO. Everything went well (despite the lower than expected yield). However, I'm a little concerned since all the posts, pics, and directions I've seen about making RSO say you should wait until the RSO stops bubbling to ensure all the ISO has evaporated.

I poured my alcohol extract into a pot set inside my rice cooker (set to cook) with water up to the level of the extract. I did this in my garage with the door open and a fan blowing across the rice cooker. To my surprise the ISO evaporated SUPER fast - it finished in approx. 30 mins - but the RSO never reached a boil itself. (To be fair, it was 97 F outside, so maybe that explains the fast evap.) I gave it another 15 mins to make sure I wasn't able to smell any more ISO, then I let it cool. In the end, I was left with your typical RSO (dark, thick, sticky, etc.).

I realize the tiny decarb bubbles may not have appeared since it was already decarbed in my oven, but I had anticipated seeing larger bubbles indicating the ISO was boiling off. But I got nothing - no bubbles at all. Due to my concern, I returned the finished RSO to a water bath and brough the water to a rolling boil - but still no change to my RSO. I let it boil until the water was nearly gone (approx. 20mins) and the temp of the RSO was approx. 185 F.

I then tried the "flame test" to see if the RSO will "spark", indicating remaining ISO - but that was inconclusive. I smelled it and wasn't able to detect any more ISO. I then tasted it. It tasted bitter - but RSO is always bitter - so that was inconclusive as well. I added approx. 1/2 tsp of canola oil to thin it a bit and have placed it in my fridge waiting for me to try it tonight.

My questions are: Was the RSO supposed to boil? Is there anything else I should do to improve it?

Thanks so much,
420Tanker

You don't boil the RSO, you only boil off the alcohol. Since a liquid boils at its lowest constituents boiling point, the mixture with isopropyl would boil at around 177F until it reaches the point where the alcohol and mixture form an azeotrope.

If you add a small amount of water, it will raise the temperature to around 212F and boil off the rest of the alcohol from the azeotropic mixture.

The FDA considers Propanol 2 (Isopropyl) a Class 3 solvent and limits residuals to 5000 ppm, but the human sensory threshold for Isopropyl is around 11 to 39 ppm, so if you can't smell or taste it, you are below FDA standards.

Thanks for the reply, Fadedawg. I forgot to mention in my original post that I did put a few drops of water into the RSO near the end of the cooking process to ensure it evaporated as well. It seemed to. If I make it again, I may try the RxCE method posted here to see how I fare.

I just wanted to report back that I tried the RSO last night and - boy does it hit hard and fast. I had the best sleep in ages. LOL. It definitely has a strong smell (probably from the oven decarb), but no ISO smell. Judging by that, I'd have to agree that any residual ISO is well below the 5000 ppm limit.

I'll stop fretting over it now and just enjoy the couch lock.

Thanks again,
420Tanker