I don't evaporate naphtha anymore. Have not done it since early on.

Assume we have two extractors (Alcie amd Bob) using bark that puts 2g of DMT in their combined napthat pulls of 500ml. Alice does not ore evaporate the naphtha, while Bob evaps half of it before freeze precipitation. We will use 1mg/ml for naphtha solubility in the freezer (-20 C) source. 5 pull in total are done and we will asume that fresh naphtha and used naphtha both converge to a 2g extraction. We also asume solvent losses are minimal and can be ignored.

During the 1st extraction:

- Bob recovers 1.75g of DMT, and has 250ml of naphtha with 250mg of DMT leftover.
- Alice recovers 1.5g of DMT, and has 500ml of naphthat with 500mg of DMT leftover.

During the second extration:

- Bob adds 250ml of fresh naphtha, recovers 2g of DMT, and has 250ml of naphtha with 250mg of DMT leftover.
- Alice adds 0ml of naphtha, but also recovers 2g of DMT, and has 500ml of naphtha leftover holding 500mg of DMT.

Third and subsequent extractions with used naphtha go along just as the second extraction.

After 10 total extractions:

- Bob has 19.75g of DMT and 250ml of naphtha leftover holding 250mg of DMT. He has evaporated/lost 2.5L of naphtha.
- Alice has 19.5g of DMT and 500ml of naphtha leftover holding 500mg of DMT. She has used a lot less solvent (0 to the evaporation step) and done less work my skipping the evap step.

At this point Bob still has more DMT. But Alice decides to do a tiny bit of more work at the end of all this. Withoht doing another extraction, She decides to evap half of her naphtha and freeze precipitate it. She gets back 250mg of DMT. She now has the same ammount of DMT as Bob, has used up 10 times less solvent, and has done a lot less work (one evaporation instead of 10).

Summary:

- Bob has 19.75g of extracted DMT and 250ml of naphtha holding 250mg of DMT, but has evaporated 2.5L of naphtha in 10 separate evaporation setps..
- Alice also has 19.75g of extracted DMT and 250ml of naphtha holding 250mg of DMT, but has only evaporated 250ml of naphtha and only done one evap step.

So I ask, if we intend to reuse naphtha, why do some TEKs reccomend the evap step on every run?

I always assumed it was for ease of precipitation. Though, I use less solvent and need to evap far less as ive gotten better.

You're right though, once in the solvent, the DMT can always be retrieved as long as the solvent is saved and reused (the jar of solvent to reuse has plenty of DMT in it too.

One love

Right. I fear we are evaporating lots of solvent for no good reason.

Maybe we should add a note to the published TEKs that instruct to evap until cloudy that evaporation is not needed if the solvent is going to be reused?

I think it is the right thing to do long term for the environment...

I agree! I think in the teks the recommendation is for new users new to extraction wanting to get all the goodies from a single extraction process. But I think as people dial in their process, less solvent should be used evaporated.

One love

Yeah, I think a new person is very focused on that final % yield and the evaporation adding 0.25% is a very juicy prospect as one learns.

However, I don't think it is the right thing to do long term. We can encourage to not evap and reuse on the TEKs. I fear some people may evap for years if the TEK they follow doesn't mention this...

You're definitely right. There's a reason that many states in the US are outlawing hydrocarbons for consumers...

One love

My head just exploded. I'm never evaporating ever again...

Luckily, I finally have an empty naphtha container that I will now keep as a "used" solvent container.

My heptane however I have always reused for recrystallization.

Great post Loveall, if this isn't stickied I'll add to my signature as it's a question that's asked a lot.

I'll update my TEK as well, as I'm still tweaking some things before I add it to the Wiki.

Never evaporate, always re-use

Same here, never started to evaporate since I always re-used the solvent.
Great that you made it clear why and how Loveall!

Naphtha is dead expensive where I am so I have always distilled off my excess solvent from a pull after the first few attempts of evapping showed me how much NPS I was gonna lose per 100g of MHRB.

Nowadays I routinely use 300ml Naphtha per pull and then distill each one down to 100ml and freeze precip that. Whats left after the DMT has come out goes back into the next pull and I top up with fresh Naphtha.

Since Ive been using this method I generally lose between 50-100ml per 200g of bark (4 pulls total) which is an acceptable loss for me.

It is a bit of a pain but distilling off 200ml doesn't take more than an hour and with the third and fourth pulls being 1 and 2 weeks after the initial pull its not massively time consuming.

Hey at least you're distilling, I've always wanted to do that.

Yeah its something we should all aspire too if we are able cos its so damn useful but my god its tedious even with such small amounts.

Dont get me started on making azeotropic ethanol from yeast