SWIM warmed up some naphta with some boiling water, the naphta turned yellow.

SWIM had put in 50mL but got only 15mL, he is guessing the rest vaporized or something.

Anyway from just 15mL he got more residue than he ever had before.

Thus SWIM is happy he finally is able to pull stuff out of the bark but is worried he may have messed up the bark with the high heat, is this possibile

He had put it in water that was just boiling moments ago

Was this a STB extraction. If so there is probably still some naphtha left in the bark sludge.

15mL of naphtha doesn't hold all that much spice. I'd add another 50-100mL and try to make sure you get all of it out.

Heating the naphtha is pointless because if your basified mimosa juice is cold, the naphtha will just cool off to about the temp of the mimosa juice really quickly. If you want to heat something up you should heat up the jug with the naphtha already inside. I use a milk jug for extractions, so all I have to do is heat up a large pot of water (not boiling don't melt the jug) and let it sit for 30 minutes or so, heating the water back up as needed (with the jug removed temporarily).