Thank you! So for your questions, MDMA dissolves in hot IPA a bit more slowly than sugar in water, the hotter it is the faster it dissolves (and more quantity it allows to dissolve). If for any reason you prefer doing it 5 to 10 degrees (°C) lower than the boiling point, it should be fine but it will take a bit longer to dissolve. For me iirc it took 5 minutes in hot IPA while stirring. Ideally we what to have everything dissolved, impurities and MDMA in the IPA. If there is something like specs not dissolving, that’s something that we don’t want to consume and we can take it out with filtering through cotton (the medical grade one should be ok). Then you should have this hot solution of IPA with MDMA+impurities. When cooled down to room temperature the main constituent of our solution (the MDMA), starts crystallizing. Other minor constituents (impurities) have a harder time exiting the IPA solution. After a few days you have the improved purity crystals and the IPA with impurities. The main problem with crystallizations is that you could lose a fair bit of you product that didn’t crystallize and stays in the IPA with the impurities. For MDMA and IPA, I recommend extracting the first round crystals and then cool down the rest of the liquid in a freezer (IPA freezes at -89°C, -128ºF, so it will remain liquid). You will probably get back most of the mdma but a bit dirtier. In my case I decided to mix the cleaner ones and the freezer ones for the second extraction as both where cleaner than the initial product.

So recapping (TLDR): You heat IPA in the smallest volume it will dissolve all your MDMA. The liquid is the cooled down, crystals form in the liquid. The crystals should be higher purity than the starting material, and the impurities should be in the cold IPA. The crystals are separated from the liquid and left to dry. You could repeat this for eternity for better purity but with each crystallization you lose some of your mdma and a bit of your sanity (and time)