A Centrifuge for Post Processing Cannabis Extracts

The Centrifuge

The centrifuge, a key piece to any lab. The centrifuge is used for “wet” extracts (sugar sauce, wet batter, anything that has liquid “terps” left in it). 

This product needs to be on heat in an oven or on a slide warmer until the visual butane reaction has subsided. No need to vacuum purge the extracts before centrifuging them, just make sure it isn’t reactive when on heat and being physically agitated. 

The function of the centrifuge is simple: use centrifugal force to separate liquids from solids. THC/THCA is a solid and terpenes are in liquid form after extraction. The centrifuge will separate the clear/white THC/THCA from the golden terp liquid.

Using the Centrifuge

Loading up the centrifuge is simple: fill the tubes to the second to top line (45ml on 50ml tube). Ensure they are balanced, weigh them with the cap on to get a true final weight, and let them spin at 7,000 rpm for 30 minutes.

Once the process is completed the thc will be a solid in the bottom of the tube and the terps will be sitting on top of the thc, separated. 

From this point I use a lab jack/stand to hold the tube and dump the liquid/terps into a jar for use later on. The solids/THC will need to be scraped out with a dab tool. This can be a bit tedious but is definitely worth it for the end result. The THC you just scraped out should be a much better color than what you started with as all the terps containing the vast majority of the color have been removed. 

Typically the THC batter you just scraped is good to go. You can add terpenes back in if you believe it is necessary to do so, but we typically don’t. We save those for cartridges. Remember - a little bit of the terpenes can go a long way here.

At this stage you should vacuum oven per your standard operating procedure, if needed. I will note I do not use n-butane as its boiling point is quite high (33.2), I use iso-butane (boiling point of 10.9), and find the butane travels with the terpenes and the batter doesn’t typically need additional processing.

Sugar Sauce & Micro Crystals

For sugar sauce and micro crystals, the process is roughly the same with the addition of one important item and a change in settings on the centrifuge. To “harvest” the crystals from your sugar sauce you will need either a platelet separator designed for your centrifuge tubes or utilize 25um (micron) rosin bags. Either of these is a good choice, though I do prefer the platelet separator as I feel it is a much cleaner process. 

You will place either of these items in your centrifuge tube acting as a catch for the sugar sauce you are about to load, you will only be able to utilize half the tube space with the bag or separator. Once the catch is loaded, cap and weigh your tubes for balance and give them a spin about 4,000 rpm for 20 minutes. 

After the Centrifuge

Once this has completed you should be able to remove the tubes and visually see the terps this time in the bottom of the centrifuge tube while the THC/THCA “sauce crystals” are caught in the catch, clean and free of the terps. This allows you to vacuum purge your crystals/diamonds separate from the terps. After the diamonds are purged add the sauce “terps” back (once cleaned by stir bar) as you and the crew deem necessary.

At this point I’m sure you’re wondering what about these terps, if we don’t vacuum purge them what do we do? Since terpenes are a liquid, they will readily release butane at room temperature through physical agitation. 

Best way to do this is buy some magnetic stir plates (preferably one that heats as well for the cold months), once you have some stir plate all you need is a jar of terps and a stir bar. 

The stir bar needs to be a samarium cobalt (rare earth) stir bar, the alnico stir bars really stink if your terps are too thick or your magnetic stir plate does not have excellent magnetism. Simply allow the terps to be stirred for a minimum of 24 hours, with the lid of the jar cracked to allow pressure to escape. 

After 24 hours, if you can observe any reaction (mainly bubbles) allow the terps to stir until they are a smooth bubbleless liquid. At this point they should be butane free and ready to be used in cartridges if the viscosity is appropriate, or ready to be added back to the THC/THCA it was removed from, or even a different batch if it needs some help.

The Centrifuge Specs

In all, the centrifuge provides a huge range of control, from how butane is removed to creating new products. The Standard centrifuge I recommend has a 6x50ml rotor and has the capability to spin to 7,000+ rpm. You should be able to find one in this spec for 6-8k range, Ohaus seems to be the popular brand although hard to get. If you can find a centrifuge with a built in heater/chiller you can do some really fun stuff, but they are like 25k+.