I've made two batches of BD using the soda bottle method, one with SVO and one with WVO. While I see separation in both, the WVO did not appreciably change in color and still has a caramel tint to it. Is this normal? Should I be expecting a more blonde product when processing dark WVO?

BD from waste oil will be darker than that from new oil, but some lighter than the oil used was before being made into BD. This is normal. Generally, better conversion fuel can look a little lighter than poorly converted fuel from the same oil. But, don't use color as a quality test. Check out Jan Warnqvist's Conversion Test (3/27)

Andrew

Thanks, Andrew. I'll give this a go.