I just had a successful extraction that yielded about .97g from 49g of mhrb. I re-x'd once and whitened it up a little bit and the total yield was about .7 of powder. The spice still had a yellow tint to it so I wanted to do another re-x and things started getting weird. I took about 15 ml of fresh bestine and covered the spice then placed in a hot water bath until a yellow blob formed on the bottom. When everything evaporated the product was more yellow than it was before I started. Beyond that, it seems like a lot of the powder/crystal became a goo, which is weird as well.

I've tried different ways to re-x this stuff but nothing seems to be working. I tried to add 15ml to the spice, warming, waiting for it to cool a bit, then placed it in the fridge for two hours then the freezer, the result was yellow crystals. I tried only adding 5ml of bestine to see if I could just keep pulling small amounts of clean spice out at a time, the result was goo and all the powder seemed to stay in the shot glass. I usually just add small amounts of bestine at a time then let it evap on a glass dish, which happens within a few minutes, but this time it's just not working no matter what I do. Anybody have any tips?

Maybe it's the temperature.
If you heat too much, the yellow has much more tendency to partly re-dissolve again rather than sink at the bottom. Rex-ing looses it's potential this way. Heat carefully, just enough to melt the spice and your naphta turns from milky to clear, no more(!), this keeps max yellow down at the bottom. Repeated reX are needed to come to white if started from deep yellow material. The yellow can take up to 50% of starting weight after few reX's. The yellow can be used for pharma and has as much potential than the white.
Try and feedback please.

I don't know why you are so bothered by having yellow DMT freebase?

The aim of the re-x in my opinion is to get rid of any residual impurities like lye not so much color.

Just because it's yellow doesn't mean its any less potent. I've got some yellow spice here that is awesome, I find the yellower it is the more way out the experience - subjective of course.

I also get crazy trips from orange/red jungle spice and some very clinical sterile trips from white white spice.

^^^ what he said.
If I do RX then it's not to improve experience.

I've also thought about the possibility that a waxy layer on the crystals could possibly prevent oxidation, but that's just a hunch. Any ideas?

It's a whole lot of extra trouble that people keep striving for considering we just send it straight back through its melting point for vaporization.

Thanks for all the replies. The reason I want to whiten it up a little is because I find the white stuff easier to work with. The yellow always comes with a little wax/goo and that stuff is a pain to scrape and a pain to get in the vial. I will try again with less heat and hopefully that will work.

I always have issues getting re-x to work well. Does anyone know the ideal amount of of fresh nap to use per gram of spice when re-xing?

I have to admit I always prefer the yellower stuff to vape but it tends to be a lot more waxier when it has precipitated, thus making it a lot harder to scrape. Friends always prefer whiter looking especially when you tell them you extracted it. (By friends I mean experienced travelers who are too lazy or anxious about extracting their own).

30ml of solvent would be fine per gram. I prefer to use a little more and dilute the solution so I don't have crystals immediately forming when the solution cools. I will generally use ~50ml.

Put it in a gentle heat bath and stir with a clean utensil until it is fully dissolved then allow it to sit for 10 or so minutes.

Hold the shot glass or beaker on an angle and you'll see all the impurities pool at the bottom. Decant it off and freeze precipitate.

Thanks will try that out.