As far as I know, denatured ethanol has added ingredients to make it poisonous to drink. The price difference however is huge.
25L of non denatured, decent quality, food grade 98% ethanol is £250 + about £700 for duty. In the UK there is a £28.74/lpa(liter pure alcohol) fee on top of the cost. I think its $27 per gallon in the states?
So I’m wondering if the chemicals added to the denatured ethanol will have a negative effect on the extract or even make the extract unsafe? Will there be residual contaminants in the end distillate?