Problem resolved.

The goo had too much oils. SWIM froze the goo, scraped it, put on some heptane and on a hot water bath just to melt the spice. Then he evaporated the heptane until it was cloudy and let the jar get cold a little bit just to let the yellow oily stuff sit, then he could separate it, and the solvent pured freeze precipitade nice white - and solid - dmt crystals.

What SWIM noticed is that if he warm the recrystallization solution too much, the oil thing will get dissolved.