Step 2 - Silting

Step 2 - Silting

Introduction

Silting is a term coined to describe a unique way of clarifying the wash of semi-polar compounds. Phospholipids, denatured proteins and water soluble compounds are the unnamed contaminates in RSO that have not been discussed in detail before. The Silting step is a modification of what the food industry does to refine cooking oils. Here is a simplied form of Chemical Degumming that removes these unwanted phosopholipids (gums) and water soluble compounds prior to distillation.

Note: Phospholipids make up the cell membranes of Trichomes, the little chemical factories that produce THC, CBD and the myriad of other cannabinoids. Using an alcohol solvent, Ethanol or Isopropyl, will dissolve phosophlipids in order to access the cannabis oils. Using a cold or frozen wash does not eliminate phospholipids from the wash, you still need to deal with phospholipids somewhere in your refinement process.

There are two forms of phospholipids to be removed - Hydra-table and Non-Hydra-table. Hydra-table phospholipids are hydrophilic, meaning the material gums up with water. Non-hydra-table phospholipids are stubborn, needing to be dissolved with acid. Fortunately, a small amount of Lime Juice was found to dissolve these lipids. With that, here is how Silting works -

An amazing discovery was made in separating these heavier compounds out of the wash. Just by pouring in saturated salt water into the Isopropyl wash, phospholipids and other water soluble compounds immediately fall out. This is know as "Salting-Out" Isopropyl, a common high school chemistry experiment. Brine now becomes our most power tool for removing the trash from the oil.

Here’s what you may see depending on the amount of phospholipids in the wash and anti-caking compounds in the salt. The final density of the gunk is determined by the quality of the extracted material. Some washes will be thick, some thin, your mileage may vary.




Procedure for Water Degumming

  1. Add 1 cup Brine to the wash. Shake hard for 10 seconds.

  2. Phospholipids coagulate and form A Snow Globe effect. As the solution settles, a layer of liquid gunk forms between the alcohol and water with solids crashing out and settling on the bottom of the jar. A spectacular Snow Globe effect happens if the salt also has anti-caking additives. (Anti-caking material is not beneficial as it leaves debris in the alcohol.)

  3. Use a Turkey Baster for small washes, or an Electric Siphon for larger washes, and draw out the alcohol leaving the trash behind.

  4. Pour the alcohol through a folded paper napkin to catch any visible debris.

Science - Degumming studies

This step works best with 99% alcohol. Lower proofs contain water that start the hydration when in contact with the plant. Having 99% alcohol allows for this to begin in the jar, rather than on the plant.

Phospholipids are refined into lecithin so the longer soak times, the darker the color on the napkin paper.

Some of the many references on water and acidic degumming -

Enzymatic Degumming of Rice Bran Oil Using Different Commercial Phospholipases and Their Cocktails [Link]

Degumming Alternatives for Edible Oils and Biodiesel Production [Link]

Physical Refining: Electrolyte Degumming Of Nonhydratable Gums From Selected Vegetable Oils [Link]

Establishment Of An Effective Refining Process For Moringa Oleifera Kernel Oil [Link]

Minor Components in Canola Oil and Effects of Refining on These Constituents - A Review [Link]

A kinetic study of phospholipid extraction by degumming process in sunflower seed oil [Link]

Tips and Tools

Tip: Use anti-caking free, non-iodine salt. Anti-caking material may add to the source of the Snow Globe effect. Pickling and Kosher salts are available without anti-caking compounds.

Troubleshooting

Join our Facebook group to discuss all the science around these projects.

WARNING: Never distill alcohol near open flame. Alcohol vapors are highly flammable so always distill in well ventilated spaces.

This oil is appropriate for oral ingesting and vaping. Due to the potential of residual salts, do not torch this oil. Torch temperatures can reach over 760c/1400f and can vaporize any residual salts.

Disclaimer: Your use of any information or materials on the C.H.S. Website is entirely at your own risk, for which we shall not be held liable. It shall be your own responsibility to ensure safe use and operation of any processes, products, services or information made available through C.H.S publications and Website.