My understanding is that they did not change the formula, but they did change the way they listed the ingredients.
I remember this coming up over at LHL, and there was a long thread about this.
A few posters pointed out that they way they listed the ingredients now made it more confusing.
Sodium hydroxide is simply lye. Soap is a by-product of a chemical reaction from mixing sodium hydroxide and a fatty acid. There is no sodium hydroxide left after the reaction is complete.
Because of this, there is actually no sodium hydroxide in CON. Listing it as an ingredient only makes it confusing.
As a side note, the primary foaming agent in Creme of Nature though, is Decyl Polyglycoside, a derivative of corn syrup.
The info on soapmaking info was pulled from the following website:
http://www.maplewoodsoap.com/FAQ's.html
More info from it follows:
WHAT IS SAPONIFICATION?
Saponification is the chemical reaction that results from mixing an alkali salt, Sodium Hydroxide, with fatty acids, namely oils and butters. Sodium Hydroxide is a base while fats are acids. When mixed together in the correct quantities, saponification occurs and SOAP is the result. Using the cold process method of making soap,saponification is not immediate. During the curing period, 4-6 weeks, the Sodium Hydroxide and fatty acids react completely with one another. Using the hot process method saponification takes about 2 hours to complete.
There is no Sodium Hydroxide left in the soap after saponification reaction has been completed!
WHAT IS SOAP?
Very simply, soap is the by-product of a chemical reaction between a base salt (sodium hydroxide) commonly known as lye, and fatty acids (oils and butters). This chemical reaction is called saponification.