Hi IAL, some thoughts:
* the yellow is more difficult to harvest the lower the temperature is, I prefer about 50 degC / 120degF to get it (I avoid 60degC as naphtha start to boil and evap);
* My yellows are easily 25 to 50% of total yield (wood dependent) , but I'm afraid my working in denser concentrations promote yellow;
* my previous batch of wood gave me consistently more oil, the new batch is way better. Previous batch max 1.7% oil included with only 1% white, new batch easily beyond 2% total yield. Wood plays a role ime;
* I've never compared heptane vs naphtha but 'it is said' dat the shorter molecular non-polars indeed take on less-easy. At 50 degC this discrepancy is of no concern imho;
* It is also said that heptane is better suited for re-crystallizing, but I can't confirm;
* It seems a good idea to acid cook, then base.
* the yellow is more difficult to harvest the lower the temperature is, I prefer about 50 degC / 120degF to get it (I avoid 60degC as naphtha start to boil and evap);
* My yellows are easily 25 to 50% of total yield (wood dependent) , but I'm afraid my working in denser concentrations promote yellow;
* my previous batch of wood gave me consistently more oil, the new batch is way better. Previous batch max 1.7% oil included with only 1% white, new batch easily beyond 2% total yield. Wood plays a role ime;
* I've never compared heptane vs naphtha but 'it is said' dat the shorter molecular non-polars indeed take on less-easy. At 50 degC this discrepancy is of no concern imho;
* It is also said that heptane is better suited for re-crystallizing, but I can't confirm;
* It seems a good idea to acid cook, then base.