Wow Mr shroom ! that is unusually good bark, perhaps .. but I'm guessing lye has added to the yeild, raising it to that 3% mark. Or you need to check your calculations..?
You can taste the lye and see it though... it should be obvious.
In chemistry terms, an artificially high yeild- one that exceeds known results, is presumed to have contaminants. So one ought to recrystalize or wash out all lye.
I admit my bias - I feel that lye-stew tek's that skip an acid solubilization of the dmt are prone to contamination. Especially since they all call for excessive lye, shovels full of lye in fact and STBs DON'T call for pH measurement. I've heard the stories, seen swim's bad lye-contaminated crystals, and tasted it ! Bleh !l ... 1.0 % yeild is a maximum to expect, I'm wondering how you got 2%...?
Also your units are wonky, .. 'litres' of H2O not ml, you mean.?
Do you have pictures too..? purity is given away by the crystal form. How does it smoke..?