Ethanol Extraction for Small Start Up

Working on starting up a small scale lab for ethanol hemp extraction. Initially I was hoping to purchase a Delta CUP extraction system but will have to wait until finances clear up around summertime. In the meantime I’m hoping to find a relatively efficient way to extract 50-100 lbs per week using cold ethanol (cryo-freezer chilled). The solvent recovery portion I already have dialed in. Looking for tips for bench top techniques basically. Thanks!


Pressurized solvent tanks in freezer to material column outside , flush into keg, then remove etho?

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I’d recommend checking out Future’s post on bucket-tek. If you are in a licensed facility, your local FD may have issues with it. Where are you located? Do you have access to Panda Spin Dryers?

My personal recommendation to everyone on this scale:

2 x Panda Spin Dryer
2 x 30L Home Depot Water Cooler
8 x Bags (link at bottom)

Fill 4 bags with material. Add 28L of ethanol to water cooler. Keep chilled with dry ice. Maintain -40C at least. Deposit 4 bags into cold ethanol. Let soak 10 minutes with no agitation. Remove bags and let them drip into a separate container momentarily. Add 2 bags into each panda spinner. Spin for 2 cycles (10 minutes total). I choose to then re-soak these 4 bags into another 28L of fresh ethanol and repeat the process.

Take another 4 bags and soak them in your original 28L of ethanol (adding more if need be) and repeat all processes again. In total, 56L of ethanol to 8 bags. Roughly 2-2.5lb per bag. About 20lb in total and takes about 2 hours. s a 1 1?ie=UTF8&qid=1525889275&sr=8-1&pi=AC SX236 SY340 QL65&keywords=Nylon+Straining+Bag-+10%22+x+23%22-+Fine+Mesh&dpPl=1&dpID=31tVGf4QqvL&ref=plSrch


As a general recommendation, remove the lids of the panda spin dryers.


How much do you use the Panda’s? Have you not had issues with the bottom motor seals failing?

I’ve bought 4 in total. Only one has failed so far. They’ve seen a couple thousand pounds combined.


Cool. I had 4 too one of mine failed real fast. They worked well while they did though.

Do you have a link to the panda lid mod? A couple of us have been looking for a bit with no luck.

My 2 pandas paid for themselves their 1st use.


I don’t know of any link specifying a mod. I just removed the lid entirely and just place it on top while its spinning. I use a tool to turn it on instead of the handle it came with (since I removed it).


Toss up a few pics of you may. I love tearing and breaking things… I mean modding them.

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Yeah fuck that lid

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Ur talking black part and all? Right?

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Yup. The entire top piece. I’m sure there are creative ways to make new lids but I have not made one.

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If it’s working it’s working

I would recommend using a utility knife to cut out the first rim of the panda lid. Carefully score the first ring until it comes off, this preserves the lid and widens the panda to the diameter of the spinner thereby removing the restriction the lid creates while keeping the lid function and on/off switch.


Does anyone have actual solvent recovery data when doing these cold ethanol extractions?

I keep running into criticism where people say you loose to much ethanol in the biomass and no amount of centrifuging can recover enough to justify on a large scale.

What is the percent recovery of ethanol for a process where the biomass is run through some centeifugation step? 75%? 85%?

I’ve gotten 95-97% return depending on material density and particle size. I’d say it’s still worth it especially if you’re not able to use hydrocarbons due to regulatory restrictions. My organic cane ethanol is 2695.00 for 55 gal ($49/gal) so I’m loosing between $2.45 and $1.22 per gallon or $22.57 and $11.24 per 9lb run.

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How many runs can you do before the ethanol picks up enough water to bring the contentration below 190 proof?

Depends on what volume ethanol vs. starting material, moisture content of starting material, as well as environmental variables depending on your tek (bucket, cls, etc) - but mostly starting material.

Get yourself a hydrometer. $10-20. You can sample your ethanol in real time using this and will tell exactly the proof of your EToH. This tool will allow you to always know the proof of your ethanol. Alternatively, you can actually use a kitchen scale and determine proof by weight - although I forget the exact formula but that knowledge is here in the forum.

As a general rule of thumb, you will use roughly 1lb to 1gal. For 15-25% flowers, you can do two runs, And for 7-12% trim, you can do 3-4 runs. This isn’t so much because the ethanol absorbs water but rather - you risk saturation of desirables in your ethanol whereby the 2nd-4th run is like a sponge and the spent starting material is now soaked with your cannabinoid rich ethanol = why the pandas were recommended to recover that desirables rich ethanol.

Depending on your recovery tek, you may or may not need to reproof. If using a still, or countertop air distiller - your ethanol will come out around 95% (190 proof). If using a roto, your mileage may vary.

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In general the extraction life of your ethanol prior to recycling/reproofing is mainly an issue of saturation and temperature control more than anything. As @Receptor_Nectar points out 2-3 reuses is a good place to plan from.