Plant Oil Extraction – FAQ

Q: Is the chiller included?
Yes. The R5 extractor includes a customized 60,000 BTU / hour chiller that’s available in either single phase, or 3-phase versions.  It provides plenty of cooling down to -20 C.
Q: How many gallons of alcohol solvent does it use?
200 – 400 gallons of ethanol or isopropanol per shift.

Q: How many pounds of plant material can it process?
Depending on the extraction procedure used, approx. 800 to 1200 pounds (363 – 544 Kg) per shift; possibly more depending on your preferred wash times and operating procedures.

Q: How cold can the solvent go?
To -20 degrees C.  For volume processing, we recommend 0 to -10 degrees centigrade; this keeps out unwanted fats, lipids and chlorophyll while maintaining useful extraction absorption. Read the next question for more info on absorption.

Q: Is the R5 ethanol extractor efficient?
Yes, it is very efficient.  But there are many variables to consider that will affect extraction efficiency:

  1. Temperature. The colder the solvent, the less able it is able to absorb. For example, when salt is added to cold tap water it takes longer for it to dissolve; so too with ultra-cold solvent. 
  2. Time. How much time is the plant material washed? Like the salt example, the longer it remains in the tap water, the more salt  dissolved.
  3. Agitation. Staying with the salt example, the more vigorously you stir, the faster the salt dissolves. The R5 extractor makes it easy to exactly adjust the amount of agitation to best suit the plant material and precisely target the desired goodness.
  4. Location. Is the target goodness external to the main plant in glands or hairs (such as trichomes, like hemp), or is it internal, deeply embedded inside leaf or seed? External glands like trichomes can be quickly extracted while internal oils take far longer.
  5. Preparation.  Is the material flaked or is it whole?  The more surface area available to the solvent, the higher the extraction efficiency.
  6. Moisture.  Is it fresh and wet?  Dried?  Somewhere in between?  The more water that gets absorbed by the alcohol, the less molecular space available for other compounds to be absorbed.

There are other variables too that affect overall extraction efficiency like harvest — is the material harvested gently or roughly — if roughly, external trichomes can be lost. Pre-chilling of the plant material will keep the solvent cold during the initial contact between material and solvent to avoid unwanted compounds. Post extraction alcohol recovery… some plant material, like hemp, holds onto alcohol very well and must be centrifuged to recover valuable ethanol and the target goodness it contains (this is often the very richest tincture in terms of desired compounds).

In summary, extraction efficiency depends on the quality of the material from harvest to pre-chilling, and the strict adherence to well-defined extraction procedures.  

Q: Is the R5 ethanol extractor approved in my state?
Probably. It has been peer reviewed and approved by Pressure Safety Inspectors, the most-recognized engineering and safety inspection company for extraction equipment.  It is approved in the following states: AZ, CA, CO, FL, HI, MD, MA, ME, MI, NV, OH, OR, PA, and WA. Additional states can be added as local laws permit.

Q: Is the R5 ethanol extractor UL certified?
No, since it does not have any electrical parts, UL certification is not applicable.  The chiller conforms to UL standard and is so stamped.

Q: Does the extractor offer agitation?
Yes, it has a powerful air-driven pump that can be precisely adjusted to suit exact extraction agitation needs.

Q: Is the extractor suitable for “explosion proof” facilities?
Yes, it has been specifically designed to work in explosion-proof rated facilities and has been installed in C1D1 facilities. Extractor support equipment, such as the chiller and air compressor is located in a nearby, non-rated room or area.

Q: Why ethanol?
A: From an extraction viewpoint, by varying wash time and temperature, ethanol will absorb the desired target goodness and little else.

Once extraction is complete, the saturated tincture is transferred into an ethanol recovery unit where 90% to 95% of the ethanol is recovered for re-use. The remaining extract is called “crude” (or hyper-tincture) and is ready for post-processing.

Q: Why is food-grade ethanol the solvent of choice
A: Ethanol is safe. People have been using and drinking it for thousands of years so there is a certain comfort knowing that ethanol was the extraction solvent.

190 proof food-grade ethanol is an affordable and residue-free solvent that doesn’t leave a chemical signature in essential oils once removed. Additionally, ethanol has antiseptic, anti-fungal, and anti-bacterial properties. It can be purchased by the barrel and is easy to handle. It also doesn’t require high pressure (unlike CO2) and it has a higher flash/auto-ignition temperature than hydro-carbons, making it far safer to handle.

Q: Can isopropyl alcohol be used as a solvent?
Only if post-processing ensures that ALL of the isopropanol is removed.  One of the best ways to remove 100% of the “iso” solvent is distillation. Isopropyl alcohol is NOT a food safe ingredient (unlike ethanol) and cannot be present in consumable products whatsoever!  The R5 extractor is approved for both ethyl and isopropyl alcohol.

Q: Can the solvent be recovered for re-use?
A: Yes, up to 95% of the alcohol may be recovered using an industrial recovery unit and re-used many, many times .  After recovery, the resulting fluid output is called “crude” or “hyper-tincture” since it is well beyond super-saturation.

Q: How can crude (hyper-tincture) be used?
A: There are many possible product paths depending on the source plant material used. Here are some of the more common ones:

1) Distill into fractions. Since it is already in ethanol solution, Pure oilwinterization is simple if you need to do so. Once any fats and lipids are removed the crude can be distilled into pure fractions. Because there’s gallons available, even rare plant oil fractions can be recovered.

Bottling hyper-tincture

2) Use “as is” for resale; many medicinal and herbal users prefer it in this form.

3) Whole plant oil. This is a molasses-like substance that is excellent for a wide range of products. Finished whole plant oil This is a very stable form of output and has a long shelf-life.

Q: What is whole plant oil?
A: It is a full-spectrum oil means that has all the soluble goodness that was in the plant material. This includes essential oils and the desirable sterols and terpenols; these components are thought to add medical value to edibles, balms, and other products.

Q: Is it economical to use less desirable parts of plants?
A: Many types of extractors prefer only the most potent parts of a plant, however, there can be a lot of value to be gained from other parts of the plant. Since the R5 extractor can handle very large quantities and because ethanol is a very efficient solvent, experimentation with the less desirable parts of the plant may make strong economic  sense.

Q: Can I use previously washed plant material?
Yes, it may be worthwhile to use alcohol extraction on high quality plant material that has been previously washed using a different extraction methodology such as CO2. Phase-change washes typically leave behind essential oils that ethanol can thoroughly recover.

Q: What else is needed besides the extractor?
A: The R5 extractor includes an industrial grade chiller and is capable of producing output tincture immediately after installation. It also requires an air compressor to drive the extraction pump (40 CFM x 40 psi).

Q: How much time does it take to run an extraction on a full load?
A: If you are seeking feed-stock for a fractional distillation system, a short-path extraction may run as little as 20 minutes. If you’re making full spectrum plant oil you’ll want everything the plant offers so a longer wash time at a warmer temperature with more agitation will work.

Q: How should plant material be prepared for extraction?
A: A common method is dried plant material ground into flakes (about the same size as parsley flakes). This method provides the largest surface area and greatest density of plant material in the extraction bags. The material can be pre-chilled in a freezer before extraction to facilitate a very clean lipid and wax-free output. Very rough dried material can be used though this will reduce the weight that can be fit into the extraction bags. Finally, fresh plant material may be used without drying. This allows plant material to go directly from harvest to processing thereby reducing spoilage, contamination, or break-down of the plant’s valuable goodness.  However, fresh material will result in tincture with water bound to the ethanol which will add time to the ethanol recovery process.

Q: Can wet plant material be used?
A: Yes. In cases where drying is a hassle or unworkable due to local conditions, fresh, moist or even wet plant material may be used. If possible, chop up the plant material and increase wash time. Alcohol recovery time may be slower due to increased dissolved water in the output tincture.

Q: Can the roots or bark be used?
A: Yes, a strong advantage of ethanol extraction is that it can work with extremely tough plant material such as roots, bark, and stems.

Q: Is this cold ethanol extraction?
A: Yes. Cold extraction is typically a very quick wash designed to strip easily extracted compounds. Typically it does not strip other, more deeply integrated components unless extra time, higher temperature, and/or greater agitation is used.

Q: Can the extracted output be reproduced reliably?
A: Provided the same inputs and procedures are used the resulting output should be close to identical.  Use post-extraction testing to verify. The input must be the same in terms of plant species and variety, grower and method of growth, the same age after harvest, and the same dryness and grind. The extraction procedures must be the same too; use the same amount of material and ethanol, temperature and agitation, and the same amount of wash time for each load. Strict adherence to plant material acquisition and preparation, and exact extraction procedures, will ensure a consistent output.

Q: What type of plant material is best for extraction?
A: The extractor can be used to extract essential and whole plant oils from many plants Rosemary extract such as rosemary (see picture at right), hops, chiles, and various powdered and flaked plant parts. Contact us to discuss your particular plant extraction needs.

Looking for an overview of the R5 Ethanol Extractor? Click here for that.


Saturate: ethanol or isopropanol that has had some amount of plant material extracted into it. The alcohol has not been reduced or recovered. Also known as tincture.

Crude: saturate that has been reduced below it’s original volume by alcohol recovery. Also known as hyper-tincture.

Distillate: crude that has been distilled via wiped-film evaporation or fractional distillation. “Clear” is a common distillate.

Isolate: crude that has been separated via gas chromatography isolation. Isolate is considered unique from distillate and tends to be highly refined into specific molecular weights. Pure CBD is an example of an isolate.

Updated: September 2019

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