The oils
| Oil | As the source prints it | Share |
|---|---|---|
| Olive Oil (virgin / refined / olive oil) | Olive-oil · 100 lb | 100.0 % |
How it is made
| Process | Full-boiled |
| Alkali | caustic soda ley of 36° Baumé · 54 lb · 36° Bé |
| Superfat | Not stated |
| Water | as the source states it |
| Iodine value | 85 |
| INS | 106 |
This is a boiled soap. A kettle soap has its excess alkali salted out and drawn off before framing, so the recipe states the alkali charged, never the alkali the bar keeps. Read as a modern cold-process recipe it would be lye-heavy.
What the numbers say
Computed from the fatty acids of the fats above. The bands are what the craft has settled on, not chemistry — a bar outside one is not wrong.
The source
Watt gives the alkali twice: 54 lb of ley at 36° Baumé, "and this amount of ley represents about 15·50 of solid caustic soda — the utmost amount that must be applied to each 100 lbs. of the oil used". Olive oil at a typical 190 mg KOH/g needs about 13.6 lb of NaOH for complete saponification, so the kettle is charged roughly 14 % over. That is not a negative superfat: the excess leaves with the spent lye when the soap is salted out. This is the clearest case in the corpus of why a boiled formula cannot be read as a cold-process recipe.
Read from the Internet Archive OCR of the Cornell University Library copy. Page numbers are taken from OCR'd running headers and may be one out where the header digits were damaged.
Read from a scan rather than a proofread transcription, so the figures are checked against the book’s own printed total where it prints one.