Decolorization of red/orange with ethanol / without non-polar solvent?

I have attempted searching for a while without finding a direct answer to my question, hopefully, someone here can lend me some well-needed insight.

I am attempting to decolorize/remediate a low-quality ethanol extraction and have managed to remediate the darkest colors, more notably the chlorophyll/greens. My attempts to remediate the remaining red/orange colors have so far been deemed futile.

I am attempting to manage this remaining decolorization in an ethanol solution, and have attempted activated carbon, diatomaceous earth, and bentonite clay so far. I have read somewhere that PVPP could possibly be used to remediate reds (tannins, polyphenols, and oxides) and I am considering attempting that next as a last resort, but not sure if there is any point in attempting further color remediation without a non-polar solvent such as heptane? (heptane is not an option)

OFF-TOPIC:
This is my first post, and I hope any mistake I might have made can be forgiven. I am not 100% certain that I have posted this in the correct sub-forum, please let me know if I have made any mistakes.
Also, I wish to share my appreciation for this forum, I have been using it a lot and have learned so much from the impressive knowledge base this place has become.

7 Likes

Where you going with this next?

Guessing distillate based on where you posted.

Then what?

Are you sure you need to remove the color before distillation to look good in a cart?

5 Likes

Correct, the end result is full spectrum carts. Not much more processing besides recovering the ethanol and decarbing.

Removing the last colors is not an absolute necessity, I am just exploring the possibility of it being done with ethanol. The end product/carts look very dark (almost black) at this point.

1 Like

Recover ethanol and redissolve in Heptane, then retry cleaning it up chromotagraphy style.
Activated Alumina works great for removing reds

8 Likes

I assume Activated Alumina works great only with a non-polar solvent such as heptane for removing reds?

1 Like

Correct, alot of these powders and color remediation techniques dont work well with ethanol, it needs to be suspended in a non polar solvent.
Make sure your non polar solvent is free of any water, using molsieve beads and drying powders

9 Likes

So NOT distillate.

Act of removing the ethanol from your cannabinoids does not == distilling your cannabinoids.

When you distill your ethanol off the cannabinoids, does your target become a vapor then a liquid again?

Then the target is not “distillate”.

Referring to the distillation of your solvent as solvent recovery and the distillation of your cannabinoids as distillation will serve as better search queries

How are you recovering solvent? Decarb? Keeping temps low here is important.

or back up and explore why/how you extracted all this to begin with? extraction temps and times? Biomass age and condition.

Actual distillate made from this material should look decent in a cart. You’d need to acquire terpenes

11 Likes

Welcome to the future @nakoyuko!

4 Likes

I see. Thanks for the clarification. Does this have to do with the polarity of the unwanted compounds?
And thanks for the additional info on using a non-polar solvent, however, I don’t have access to the proper testing equipment to ensure complete solvent removal or measure solvent ppms, therefore I am not comfortable using heptane, and would rather use a safer solvent such as ethanol. I am also not that comfortable handling heptane due to it being less stable / more explosive than ethanol.

Polar solvent litterally just washes the powder.

Non Polar Chromatography allows you to get compounds “stuck in a powder”

A polar solvent will free the compounds from said powder.

4 Likes

I see. Thanks for the clarification on my mistaking this for distillate when it is not.
So this post would be better moved to the sub-forum “Solvent Recovery” or “Pre/Post-Processing”?

I am recovering the solvent using a rotary evaporator. Due to cooling limitations and following the 20/20 rule (celsius degrees difference between evaporation flask, collection flask, and condenser coils respectively), I am evaporating the ethanol at a temperature around 45-60c (113-140f).

Then after the complete evaporation of the ethanol (using a fresh collection flask), the oil bath gets turned up to 140c (284f) for decarbing. Once the oil bath reaches 140c (284f), the evaporation flask is swiftly removed from the oil bath to ensure the decarbing stops at that point.

The extraction process is rather unique here, due to localization and price margins.
Considering the cost per gram of cannabinoids, the most cost-effective starting point here is actually hash (except of course trim - which is not as readily available). 100g (3.5oz) hash is dissolved in 1 liter of 96% ethanol (33fl. oz.) - then subsequently filtered through a lengthy filtration and winterization process to remove undesirables (filtration/winterization is done in 6-7 stages).

Due to using high-quality hash of unknown origin, the biomass age varies a lot; from weeks to months of age. Perhaps even up to 1-2 years of age on rare occasions.

This is the resulting end product/carts:

The quality of the carts is actually very decent. No bad flavors, and very potent. Was just hoping that there was a way to remove the remaining colors without a non-polar solvent - which it seems not. Of course, adding terpenes is done, but that does not affect color much.

3 Likes

That makes a lot of sense! Appreciate the explanation.

If it aint fresh you got no chance barking up that tree lurking cat…

1 Like

yep, with that starting point (hash), the color is not unexpected. the temps you are recovering solvent and decarbing at are not doing you any favors, but the primary issue is definitely your starting material.

non-polar solvent or distillation of your cannabinoids probably you best bets. crashing the THCA out might be an option, but the decarb level on your starting material is likely all over the map, which would make that approach unreliable.

4 Likes

The only way youre going to get reliable results will be sourcing fresh material. Preferably something that has been stored cold if that is not an option. The major cause of red coloration is oxidation as opposed to the others you mentioned. With ethanol alone theres not much you can do here that I have ever been able to find.

That said - a quick trick would be to try decarbing in your roto under vacuum to limit the oxygen available when heating (which increases process oxidation significantly). This wont undo the existing oxidation, but does significantly limit further oxidation compared to a hot plate.

If your process requires old material, might pivot to a different product line than vapes. EHO vapes can be challenging as is without that being a factor.

4 Likes

I will keep in mind for future reference to attempt to use more lightly colored and fresher hashes if possible.

Regarding operating temperatures:
Would I be better off minimizing solvent recovery temperature, perhaps closer to room temperature?

And regarding decarbing, I was of the impression that the optimal end temp should be 140c(284f) in the oil bath when decarbing with a rotovap. Do you believe there is a big difference from say 120c(248f) for 20-25 min vs immediate removal of evaporation flask once it reaches 140c(284f)?

Fresh material. Noted. Thanks. I will attempt in the future to acquire fresher material.

I do decarb under a vacuum in a rotovap to limit muffin/bubbling, never thought about the minimization of oxidation, thanks for the input, I will continue decarbing by this method.

For the time being the market here is far from saturated with high-quality vapes, so thankfully it is not an issue at this point.

1 Like

I read somewhere that activated carbon>W1>activated alumina>D.E.
is a good one. I forget the ratio of powders to material though.

Not sure how well it works. I only do activated charcoal and D.E. for my etoh clean-ups but I’ve hit red before too.

Suggested to me was always the AA or W-1 but I never used them or tried it.

1 Like
1 Like

Bentonite clay will work better with ethanol if it’s cold. I only got to -30 when I did but it did a good job at keeping color out when distilling. If you can get really cold (-80) I’d say test it out by filtering through cold bentonite plug and see what happens.

3 Likes