Does this look like heads or lipid contamination in this disty?

[tetramethylsilane]

EDIT: Posted pictures further down in the thread.

Ran a distillation yesterday and everything seemed to go well - sort of. I came in today and noticed my disty flask had a cloudiness to it, thin white cloud looking things. Sorry I didn’t have my phone so I couldn’t get pics but will take some tomorrow.

I know that cloudy disty can often be due to improper winterization. The crude material that was distilled came from a cold ethanol extraction. I extract in buckets inside a -80C freezer. Most of the time, the temp will get as warm as around -60C due to removing buckets, and spinning bags in panda and what not. This extraction got to about -50 or -55C by the end of the extraction which was ~25lb (of extremely low quality trim) in 10gal ethanol.

I can’t seem to find much info as to what the warmest ethanol temp one can extract in and avoid a separate winterization step. I’ve never winterized before - tried it once, got no precipitate after 24hr in ethanol at -80C so I figured I didn’t need to and I was extracting cold enough to avoid it. Was -55C for this extraction warm enough to pick up enough fats and waxes to result in a cloudy distillate?

My other thought was that this was heads contamination, and I’m kind of leaning that way. I only have 500mL round bottom flasks. Normally those are the appropriate size for my batches. However this last run I distilled about 2x as much crude as normal, so instead of collecting tails as normal in the 3rd flask (3 way cow), I collected the continuation of mains in that third flask, and then switched back to heads to collect the tails.

What I noticed today is that only the first of the two main body flasks appeared cloudy - the one most likely to have heads contamination. The 2nd of the two main body flasks looked fine, although a little darker. But no white haziness. So my question is, will distillate appear cloudy with major heads contamination? I noticed that the heads fraction of this distillation was also quite a bit cloudier than normal.

Another reason why I suspect heads contamination is that this distillation was rather rushed. Normally I distill up to 700g of crude in a 2L SPD. My SPD sucks - GL 18 connections, not full bore, and a very underpowerd pump (Welch CRV 4 pro 2.8cfm…) So even with only 700g it takes me ~8hours to get thru a distillation. This time, with double the amount, I rushed things a bit and it’s very likely that I didn’t properly pull all the heads out.

I know the answer to this problem is probably just to winterize it to be sure, but I’m really hoping I can fix it by just running a 2nd pass.

Sorry for no pics, I know those would really help answer this problem. I’ll update tomorrow with a bunch. Thanks for reading!

[midsfactory]

@tetramethylsilane

What I can tell you is that -55 should be good without winterization. If this is a normal temp for you and you haven’t had problems in the past, I wouldn’t worry too much. I know redissolving back into solvent is not optimal.

Again without pictures it’s hard to say, but it sure sounds like it could be heads.

[Thetetraguy]

Your answer is yes.

[cyclopath]

@tetramethylsilane

I’ve never winterized before - tried it once, got no precipitate after 24hr in ethanol at -80C so I figured I didn’t need to and I was extracting cold enough to avoid it.

ah, but did you reduce your solvent volume after extraction? winterizing is done at a 5:1 to 10:1 solvent to oleoresin ratio. too much solvent, everything stays in solution. too little solvent, you drop the good stuff too.

done quickly, -40C works to avoid most fat pickup. presumably -20C or even 0C can be made to work if you’re fast enough. I haven’t got any solid data warmer than -40C

[tetramethylsilane]

Yeah, it was concentrated to ~10:1 ethanol:oil

[cyclopath]

Just double checking

[tetramethylsilane]

Ok took some pictures.

Here are a bunch of pictures of the flask with the cloudy distillate:

Here is the heads flask, what I had to do is collect heads and tails in the same flask. You can see the cloudiness here - this mostly came from the heads. The tails portion looked fine.

So, does this look more like heads contamination or fats/lipid contamination?

[Demontrich]

Vac oil or lipids/waxes

[tetramethylsilane]

Unlikely to be vac grease. I got vac grease in my last distillation and it looked considerably different. More globular. And after that incident, I barley used any grease this distillation. You don’t think it could be a lot of heads contamination?

Does anyone know where lipids distill relative to heads and mains?

[TNhomegrown]

Definitely need another pass if cloudy. With that setup, I would always perform a 2nd pass

[tetramethylsilane]

Thanks for the reply! Going to run another pass tomorrow and hope that clears it up. Have you experienced cloudy distillate like this before that was cleared up thru a second pass? If it’s heads contamination that should do the trick I would hope, but if it’s lipid contamination, perhaps not?

Yeah I hate this SPD, although most of the time I can get good color (light yellow in carts) distillate that tests b/w 80-85% with no cloudiness. In the process of upgrading to a 5L full bore. Can’t wait.

[TheGratefulPhil]

You ought to winterize it first in ethanol and then repass it!

Looks a lot like waxes/lipids.

[tetramethylsilane]

Yeah that’s the safe bet, I know. But this extraction didn’t get too much warmer than any previous ones (this one got up to -55 or -50C while most don’t warm up past -60C).

I only have heptane denatured ethanol on hand at the moment too. It seems most people use 190 proof undenatured to winterize. Will 5% heptane dissolve too many lipids to make winterization effective with that solution?

[tetramethylsilane]

This thread:

negligible amount of fats + lipids

greetings I was looking to speed up processing if possible cutting out unnecessary steps…currently running crude that was extratced around -30c there is a small amount of fats and lipids left a few grams out of 1000gs after 3x filtering at -80c . My question is , is there a negligible amount of fats and lipids you all have found that doesnt decrease the potency/ clarity of the distillate? if not can the fats be fractioned out pre thc? thanks for your time

And some others I’ve been reading indicate that -50C shouldn’t be warm enough to pick up enough lipids to have this issue. Granted there are only two posts in that thread, but I get the impression that @MagisterChemist knows his shit.

[TheGratefulPhil]

I can say with certainty that lipids are soluble in pure heptane at -50 or even -60C.

I’m not sure how the coexistence of heptane/ethanol affects solubility of those lipids—so it’s hard for me to say with certainty.

Maybe retain a small sample of the first pass and get you some everclear and try winterizing with it. If you pull fats then you’ll know that was the primary contaminant

[tetramethylsilane]

Yeah I’ll be ordering some non denatured ethanol and some methanol tomorrow. Definitely need to have those around for situations like this.

[MagisterChemist]

I got much better clarity than this winterizing at -20 with heptane-denatured ethanol. So i really doubt that is the cause.

[tetramethylsilane]

Thanks for chiming in! Any thoughts as to what it may be? I suppose it could be vac grease, but I applied such a small amount that I have a hard time believing that to be the cause. Serious heads contamination? That’s my thought, also the easiest to fix, so I’m hoping that’s it. Thanks for looking!

[Midnightoil]

Artwork from science👏

[tetramethylsilane]

Yeah the heads flask looks cool, lol.