I keep a bit of bio back from every batch, store it in cubies, and use it through my space heater in the winter months.
Last winter with a combination of mild weather and longish covid , I have around 100 litres that are at least a year old.
It won't ignite in my space heater, fresh bio, no problem as I've tried it.
What's the best way to use it, a bit every fill up or can I reprocess it?
Best way or method to reprocess?
TIA.
Chris.