Recreating vintage Williams will be CBL’s next challenge!
That was exactly what got me started on making soap. I believe I have come very close by incorporating old methods into my process.
I honestly believe aging plays a role but as @kingfisher suggested, there is a time at which (in theory)all the chemical processes have gone as far as they can and the puck is in a state of equilibrium. Having done a lot of reading on old processes (as Walt appears to be doing as well) I am inclined to say the old ingredients and processes are as much to blame as the aging. I am sure the methods of mass production today aren't necessarily very different from the "old" way BUT in soap making the small things matter. Maybe its magic.
The old ways pretty much always involved boiling the fats in a mixture of lye and water. Salt (sea salt probably) was added to the "batter" and the soap curdled and floated to the top. The liquid below the soap contained any left over lye, water and all the glycerin was created during saponification. The old soap makers would then boil the soap again in a weak lye solution to ensure all the fats had been saponified, then add salt again to force the soap to float to the top. The French methods used today still do it this way, often boiling 3 or more times to ensure purity. The problem with this method was that it removed (removes) the naturally occuring glycerin. Many Soap makers would then go through a process to recover the glycerin so it could be sold for other uses or added back to the soap to improve its performance.
By contrast, today's artisans (and possibly commercial producers) carefully measure fats, water and lye so that when boiled together the resulting product is completely saponified, still has its natural glycerin and contains the desired amount of water. Kind of like a making hamburger helper on the stove, in one pot.
Even though the end result is essentially the same and could conceivably be labeled with the exact same ingredient label, I believe the "HOW" is important and influences the "WHAT" we get. While I don't boil and salt like the old methods, I have done so and many of you have been given a sample of that soap (it was mid beta 3/Damascus). The old ways are far better applied to bar/bath soap than to shaving soap. That said, I have incorporated several aspects of the old ways into my process. It adds some extra time to the process but I would like to think it matters.
Dissecting the vintage williams labeling I am prepared to propose the following:
The old labels indicated Sodium Tallowate, Potassium Stearate, Sodium Cocoate, Water, Glycerin, Fragrance...and stuff. The label tells me they boiled Tallow and Coconut oil (probably at the same time) in an excess of Sodium Hydroxide lye, while boiling stearic acid in Potassium Hydroxide lye. They probably used a salting method to remove the soap from the lye solution and MAY have even double boiled (why not? that is what soap makers did back then). Once all the soap was collected, rinsed and pressed dry, they added glycerin, fragrance and a few preservatives (at least one is also a chelator that would improve hard water performance). This method would produce a very pure soap whose formula suggests it should be slick and easy to lather into a creamy consistency.
Dissecting the modern label I propose how things might be done differently today
New labels indicate Potassium Stearate, Sodium Tallowate, Sodium Cocoate, Water, Glycerin, Fragrance, Sodium Chloride, Titanium Dioxide (preservative), Stearic Acid, ...and stuff. and MAY contain Sodium Palmate. Palmate is quite similar to tallowate and often called "vegan tallow". This label seems to say the major components are largely the same but in VASTLY different amounts. Specifically the stearic acid is present as the primary saponified ingredient and again as a buffer. I suspect the old formula had as much as 72% tallow, the new version looks like it would be half that. The presence of Sodium Chloride and stearic acid as separate ingredients suggests to me that they manufacture modern williams using pre-saponified components. They might buy or manufacture the potassium stearate, sodium tallowate and sodium cocoate as separate components that are later mixed together. Regardless of the process the label has me convinced the old and new are not the same product. In fact the newer product SHOULD be easier to lather, better face feel and have a lower potential pH all because of the amount of Potassium hydroxide and stearic acid used
If pressed to give a reason why the older product is so wonderful i would say it has to do with the process resulting in higher purity of soap. Aging may allow for oxidation or some other process of further refining the finished soap. Maybe aging to the point the fragrance molecules are gone does something.