Bleaching Clays Part 1 Posted on 30.08.2018 at 17:57. I have a keen interest in bleaching clays. I first discovered them in summer of 2016 when researching adsorbents for use in cannabis oil treatments. People have varying opinions on the use of clays. It is true they can induce isomerization under certain conditions. It is also true that they are not always necessary. The practice of using these clays usually takes a fair amount of optimization and experimentation. The first video I saw on bleaching clays was from Tonsil. I STRONGLY recommend everyone watch this video from start to finish: Fascinating, no? It goes much deeper than what this video presents but its an intriguing starting point. Notice in the video they refer to pesticides as “crop protectant residues.” Yes, bleaching clay can also help remove pesticides. But I recommend magnesium silicate-PR grade for that purpose. Bleaching earth is primarily composed of montmorillonite, a silicate. They are activated via acid sometimes or left neutral, or even alkaline. The activation process is to remove cations contained in the clay to make room for adsorption of undesired compounds (see video). If one wishes to use these clays, there are several well-known principles set forth to keep in mind when developing one’s method. I will outline the ones I have found most important(1): 1. Keep opportunities for oxidation, thermal damage and hydrolysis to a minimum. 2. Choose the lowest practical process temperature. 3. Bleach under light vacuum (or inert atmosphere, see no.1). 4. 30 minutes max is enough! 5. Add adsorbent below the temperature at which one wishes to react. 6. Phosphoric and citric acids can help scavenge trace metals (but they can also cause isomerization of D9-THC to D8,D10!) 7. A smaller dose of more activated clay is cheaper and less likely to cause trouble. 8. Since everyones oil is different and things such as starting color, desired final product and purity are treated as variables, this list is a guide, not a rule. The special thing about cannabis oil is of course that it contains a special active ingredient. Therefore one must be extra careful when evaluating their method. Some of the variables to consider with cannabis oil are: Starting Color- Desired color Starting Potency- Desired potency Chlorophyll content Peroxide value- Primary oxidation Anisidine value- Secondary oxidation Moisture content Phospholipid content (gums) Heavy metal content In the next installment, I will go over each of these variables in more detail. I find the oxidation topic particularly interesting. Bleaching clays are nothing if not intriguing.