SWIM followed 69ron's d-limonene mescaline extraction with 2 small variations: 1) used 70 g powdered San Pedro cactus instead of 100, and 2) used food-grade NaOH instead of Ca(OH)2.

SWIM added 300 ml water to the cactus powder, ~25g NaOH, and ~300 mL d-limonene, mixed thoroughly, and let it sit for 3 hours. However, when SWIM tried to filter it with a french press, the green cactus sludge was so thick it almost broke the filter! SWIM was not able to remove any liquid from it whatsoever.

Is this because SWIM used NaOH instead of Ca(OH)2? Can swim get around this by adding more NaOH?

NaOH is not all that great as it doesn't break down the mucilage in the cactus that Calcium hydroxide does.

Also.. a drytek with NaOH?!?!?! That's crazy!

This won't work! Sorry!

well was there an ammonia smell released when mixing?

as NaOH is so strong it should all be based very nicely if you mixed it really well, but try letting gravity + time get the limonene out.

Worst comes to the worst convert it to a wet tek, but that's the last possible solution situation.

So wait, did you add water, limo, lye, and cactus together at the same time, or did you add the ingredients as advised by the tek?

There was no ammonia smell. A little bit of the cactus mix turned brown when SWIM (carelessly) added all of the NaOH at once, but that went away quickly with mixing.

SWIM did not follow the tek 100%. Aside from the aforementioned deviations (70 g instead of 100, NaOH in place of Ca(OH)2), SWIM added water (~300 mL) and THEN NaOH. SWIM believes that tek called for the solid base to be added to the cactus powder before the water, but doesn't see what difference this could make.

Shouldn't the hydroxide ions be what is breaking down the cactus muclage? I don't see what the counterion (i.e. Na+ or Ca2+) could have to do with the process.

SWIM just got food-grade Ca(OH)2 and is going to try adding it. Will update on how it goes.

High pH (i.e. loads of OH-) does break up the mucilage. This however takes time, so in a cactus STB with NaOH it may take around 2-3 days for the solution to become "more" liquid. Heat does the same by denaturing the mucilage and prolonged boiling of the cactus also breaks up the mucilage to a good extent.

Calcium ions however seem to be doing the job in 69ron's tek. Calcium has the great ability that its salts are usually insoluble (or very slightly soluble) in water, like calcium phosphate, calcium carbonate, calcium citrate etc. An attractive therefore theory is that the calcium from Ca(OH)2 forms calcium salts with the cactus proteins and polysaccharides, makes them insoluble and thus their appetite for interacting with water goes away.

Think of the cactus mucilage as something like hyaluronan (anionic polysaccharide) or even heparan sulfate (another anionic polysaccharide) that can potentially bind and form complexes with calcium. Both hyaluronan and heparan sulfate have the properties of absorbing water and forming gels, hence they are naturally used in our connective tissues to make soft substrates and most of our "squeezy" bits!

Update: added ~25 g Ca(OH)2 and the cactus sludge changed color and consistency quickly. It went from a dark green and heterogeneous to light green and more or less homogeneous; it also became slightly less viscous. SWIM let it sit for 2 hours and then tried filtering it through the french press again, but with no luck. SWIM pressed down hard with the press, but the green goo that came through the filter was the same color and consistency as the rest of the green goo (i.e., it doesn't seem to be filtering anything out). SWIM would appreciate any help!

Gravity and patience.

Trust me I know the goo. the only thing that can save you now is to make the vessel horizontal and hold a potato masher to the side of it to hold the goo in. the limonene should slowly drip out.

If nothing happens after 2 hours you may want to change to a wet tek... but that involves having to do a shitload more pulls to exhaust the cactus.

SWIM left the water-NaOH-Ca(OH)2-limonene mix out all night and it began to separate very slowly. After being out for about 12 hours, there was about 8 mL of liquid floating on top of the green goo.

Can anyone tell me why it formed this "goo"? SWIM still has more cactus & wants to use 69ron's limonene tek, but is worried there might be something about his cactus that is intrinsically goo-forming.

Update/bump:

SWIM let the limonene-cactus-lime mixture sit overnight and sure enough, it started to separate. A layer of d-limonene appeared on top of the green goo and grew as the day went one. Once SWIM could get ~100 mL off of it, he filtered it out and began extracting it with vinegar in a sep funnel.

Now SWIM is on his 2nd pull, but got some greenish-white flaky stuff (plant fats?) in his first vinegar extraction. The vinegar extractions from the first limonene pull did not have this junk in it. Could this be a problem? Can SWIM just re-dissolve all of his extracts at the end, and then filter them to remove this flaky stuff?

Any help would be much appreciated!

After separating the limonene, did you make sure to run it through a coffee filter?

Yes, SWIM did. With his second limonene pull, he ran it through 4 coffee filters - and there is still this white gunky stuff in the water layer when he extracts with vinegar.

FWIW, there was the most white gunky stuff on the first vinegar extraction, slightly less on the second, and even less on the third. Is there any way SWIM can filter it out? If he uses actual filter paper instead of coffee filters, could that help?

SWIM feels like this must be a common problem, there's got to be an answer somewhere...

And?

CaOH2 gives 2 moles of calcium hydroxide per mole if completely disassociated, NaOH only gives one, If you added same volume, you might have had only have the base needed. Just an idea, maybe adding twice as much NaOH could have helped. just thinking, sorry coulndt read whole thread gotta run to class, hope it worked out