Hello everyone, I ran into an issue currently and appreciate any help with this problem we have encountered.
We started out with raw crude that was extracted with ethanol. That crude was diluted at 9 to 1 in ethanol in our jacketed reactor at around 70C, mixed for about an hour, and placed in 5Gallon buckets and put in our freezers at -45C for 15 hours. We then took our ethanol/crude mixture and filtered it through our sambo filter, using two 5micron filter papers, and filtering directly from freezer to filter. We only filtered through our sambo once because we tested one 5gallon bucket by filtering it twice and on the second pass of filtering, no fats were present. So we proceeded with filtering all ethanol/crude material only once.
We then proceeded to Rotovap our material at 55C and 50RPM for the majority of the process and then finishing at 75C during the final hour of our process once minimal ethanol was visible in the condenser.
After recovering ethanol, we placed our crude in a 20L steel pot at 125C with an overhead stirrer and began to decarb our material. Normally we try to decarb at 125C for an hour, but bubbles were still present after an hour and we continued to decarb for an additional hour, 2 hours total. Once we began to transfer our crude to our feeding flask on our WFE, we noticed a range in size from very fine sugar sized crystals to pebble sized crystals. This has happened once before with other ethanol material and caused our WFE feeding flask to clog. Any help appreciated.
What color are they? Have you done any solubility tests on the crystals? Are they are water or alcohol soluble (or both)? If they are water soluble, I have some ideas about what they may be.
I have had a very similar precipitate form when applying heat to ethanol crude. From solubility tests I conducted, it was soluble in water but only partial soluble in isopropyl, acetone, and ethanol. It was entirely insoluble in heptane although I did not handle it as extensively with heptane due to limited volume at the time.
From what I have heard, it may be water soluble compounds (such as sugars) from the plant material that gets pulled through during extraction.
I generally will pour off the top layer, reintroduce ethanol to the “sugars” and filter them out. They don’t seem to form on the next round of roto-ing.
Thank you both for your replies. The crystals are clear/white in color and we are testing them in water and 190 ethanol. I will give updates on the results shortly.
I wouldnt run that, sugar is bad
Water test: roughly 1.5 to 2 grams of crystals in 2 cups of water. After 10 minutes, the crystals haven’t changed in size but they have formed together and are stuck to the bottom of the jar. Not disolving
Ethanol test: roughly 1.5 to 2 grams of crystals into 2 cups of 190 ethanol. After 10 minutes, crystals have broken down into smaller pieces but same initial volume of weight is present. Not disolving
Use hot water, if it feels and looks like glass its sugar make sure you devolitize up to 300 degree s for cbd
Didn’t use hot water initially. Going to retest now. We are using THC crude material, not CBD, although im sure a small percent of CBD is present.
When taking out the crystals from the initial room temp water test, they do feel and look like glass
Ah well if it turns out to be the nasty stuff I think it is maybe try some LLE or degum enzyme, its difficult to refine
You should try agitation with both methods. I prefer (as I was taught by @cyclopath) to take some of the crystals in hand and add a small amount of solvent (water or ethanol) and proceed to stir and press with a finger. If it dissolves, its soluble. 
We tested water and ethanol on the crystals with agitation and pressing of finger. With the ethanol, the crystals disolved completely when pressing and agitating. With the water, the crystals disolved completely with agitation and pressing of finger.
That’s really weird. I haven’t run into anything in my extractions that have presented at that stage of the process that were not soluble in only one or the other. All of the problem precipitates I have dealt with do not behave in the manner that yours does. It has me really scratching my head. Everything I can think of is monosoluble. Sorry I’m not more help on this one. Hopefully someone will have a better answer than me.
Edit: Do you have a COA on the crude? And are you working with CBD or THC based crude?
So let me clarify, during the water test we rolled the crystals around our hand with very minimal pressure and the crystals evaporated by themselves. With the ethanol test, we applied much more pressure from our finger combined with rolling them around and they wouldn’t have broken down without the added pressure from our finger. We just retested and they dissolved in water with minimal agitation, they did not dissolve in ethanol with the same amount of pressure.
Seems like it could be sugars (and/or other water solubles), but I am still not totally convinced. If it is sugars, I do something similar to what @OilArt suggested above. If the crystals won’t dissolve in ethanol, bring your crude back up in ethanol to reduce viscosity and filter down to 1.5 um. The more ethanol you add, the faster it filters. Consequently, the faster it filters, the more time in the rotovap. I vote for rotovap time over filtering time.
You could do LLE (heptane/water) to remove the sugars prior to the first pass so that it doesnt damage the internals of your system. Can be done relatively quick with the right gear.
Did you taste them?
@Akoyeh skipped that part 
I know we’re not supposed to eat stuff of the sidewalk, but tasting all my extracts has been a very informative part of my learning…
it’s also made for some amusing work days…
The “dab it where it lays” rule for dealing with spills was also a crowd pleaser.
It had to go once the cameras came online…
To confirm it’s not sugar, try to dissolve some in isopropyl alcohol. Sugars are much less soluble in isopropyl alcohol than they are in ethanol or methanol.