Soap Noodles — Frequently Asked Questions

It is the proportion of the noodle that is actual soap, as opposed to water, glycerine, salt and other residues. Seventy-eight percent is a common laundry grade, while 80 percent and above is used for toilet soap. Higher TFM gives a harder bar that wears more slowly in use, so it is the single most important figure in the specification.

The blend of palm to palm kernel oil the noodle was made from. Palm oil contributes long C16 and C18 chains that make the bar hard and slow-wearing but slow to lather. Palm kernel oil contributes twelve-carbon lauric chains that lather instantly but soften the bar. Raising the kernel fraction buys foam at the cost of bar life, and the ratio is chosen accordingly.

Because it removes saponification and drying from the operation. Those are the capital-intensive and effluent-generating stages of soap making, requiring caustic handling, reaction vessels, glycerine recovery and a vacuum dryer. Buying noodles lets a manufacturer run as a finishing operation, milling, perfuming, colouring and stamping, with far lower capital cost and regulatory burden.

Moisture, free caustic alkali, sodium chloride and colour. Free caustic alkali matters because excess unreacted alkali makes a bar harsh on skin; moisture affects hardness and shrinkage in storage; salt affects plasticity during milling; and colour determines how much titanium dioxide or pigment is needed to reach the target shade.