Iso vs ethonal

So other then the major price difference can we talk about the pros and cons of using iso vs ethonal.

For our process we work with dry sift cause the amount of trim we have comming in we can wash it. Just makes a lot more sense to freeze the material then we shake with dry ice and tumble. We legit get buckets and buckets full every run. After we do a 10:1 iso/sift. Would we get a lot more return if we washed the sift with ethonal vs iso? How does it effect the end product by using iso. Any and all help negative and positive is appreciated for us…

And we need to start a topic on how we can all give back to @future4200… paying it forward and people helping people seem to be the way this site has been working. Soon I’ll be posting videos and pictures of our methods. Hope something will help others


I’m hoping @Photon_noir will chime in on this one. He makes several strong points as to why you should use ethanol vs iso.

You can pay me back by spreading the word!


This is just my personal experience so take it lightly.

Ethanol seems to pull a lot less waxes, fats, etc than iso. It also seems to be a weaker solvent of these byproducts. This makes winterization easier since it has an easier time forcing precipitation. Iso was just a disaster for me.

I went to @Shadownaught for my Ethanol and it’s working amazingly. They have good prices as well on some DN EtOH.


@EndlessOps The ethanol:water azeotrope is an almost perfect solvent for cannabis resin, especially at low temperatures. It has the unique ability to pull only cannabinoids and other components of the resin without pulling epicuticular wax and vegetable oil. Isopropyl alcohol has a higher affinity for wax and some oils than ethanol does. It also has a higher boiling point and sticks around more readily than ethanol. Using an azeotrope, however, of 87% IPA to water may make it behave a little more like the ethanol azeotrope, but that b.p. and stickyness will still exist. The best option for price may be to use a mixture of ethanol:water:isopropanol, since this effectively combines two binary alcohol:water azeotropes and could be considered a type of denatured ethanol.


So I can’t link the entire article because it’s proxy’d through my university library account, but this picture sums up the discussion nicely. The oil here is cottonseed oil:

Mod edit: Link to article in Data Dump


@TheGratefulPhil Thank you! What is the x-axis in this graph?

Sorry, I knew I should have clarified that part: x-axis is temperature in Celsius. BP is boiling point. Once I get a read through I’ll post other relevant images, if there are any.


I figured as much, just by the little b.p. tags, but thank you!

Would you mind if I cut out that graph for use as an explanatory photo for a post on my instagram? It makes my point very obvious!


Not sure the graph directly applies to our extraction. They were pursuing a solvent that had good triglyceride solubility at high temps, but poor solublity at low temps. So that graph accurately describes why an ethanol azeotrope would be ideal for Winterization in our case


Please feel free to use the image, I doubt I’ll get into much trouble if i’m found out.

@Future, if I may: given that most folks are cooling below 0 Celsius it is likely that these solubility curves meet at subzero temperatures.

However, it might also be nice to try out an absolute ethanol or isopropanol during the heating step—this will provide the highest possible solubility, then to add water to dilute the respective alcohol to its azeotropic concentration as you cool. So you both have the benefit of highest solubility and lowest solubility.

What do you think?


If you added enough water to a supersaturated etoh solution as it cooled, think you could get THCa to crash out?


It is not even a full page and apparently @Future had that paper in his free data dump, anyway.


@TheGratefulPhil @Future Yes, it could crash cannabinoids out due to local variations in the solution, but they should redissolve… unless you go slightly over the azeotrope, which is way too easy to do.


Correction, I added it as soon as I saw @thegratefulphil post this


@Future added what? Also, I would like to talk to you about some of the peculiarities of this site at some point. Please call me when you have time.

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Oh! I get it. You added the paper to your collection.


I’ll start with a Thank You. You’re, along with everyone elses’, insights have been helpful.

In order to maintain a stable solvent:water ratio I’ve been looking at various ways to remove water after a cryo-etoh extraction with the assumption I’d be gaining water to the mix reusing etoh multiple times (though don’t have direct experience yet).

Would you be willing to comment on the extraction efficiency solvent:water ratios at various cryo-temps? Also best practices on how to maintain those ratios?

I’ve seen various molecular sieving materials used inline during evaporation, or solvent transfers. Is one more desirable/ affective at removing water than the other?

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I don’t have access to this but it might help. Ternary phase diagrams for ethanol, isopropyl, and water are hard to search for because ethanol water solutions are historically purified through the addition of an organic compound like toluene or benzene. so typing those words in gives a lot of similar but unrelated info. The added compound in the above situation is called an entrainer. This paper seemed to be talking about what you all were after.


Thank you, @Bonevader! Can you grab this one, @Future ?