Have you heard anyone talk about storing your extracted oil in a cold dark place, or freezing it for storage. While botanical oils look and feel like cooking oil they are untreated organic plant material. And just like a tomato left sitting on the counter, botanical oil extracts can go bad and/or grow mold.
As you prepare to make an investment in a piece of extraction equipment for botanical oils, keep in mind that you are actually purchasing a piece of food or biopharmaceuticals equipment (often abbreviated BPE). There are several codes and regulations regarding how BPE must be manufactured, tested and cleaned. The last of which (cleaning) is not just a process, it must be designed into the system. We continue to see extraction systems on the market that have sealed solvent storage tanks-these are a major design error. The solvent never gives up 100% of the oil it extracted, the residual oil left in the solvent is typically referred to as carryover. The sealed storage vessels build up a layer of carryover oils on the inside walls, which just like the tomato on you counter start to rot and decompose over time. If you are unable to thoroughly scrub and clean the inside of every pipe, valve, and vessel on your system, it is only a matter of time before the product that you are selling will be oil laced with the rancid remains of your previous extractions.