Milling soap

At one of my markets the other day, a woman politely but firmly told me that she only uses triple milled soap. 

I wanted to ask whether she had any idea what milled soap really is. But instead I smiled politely and a little wistfully, as if to say, "Oh well, I guess you've got me on that one!  I only make natural handcrafted soap!"

Milling soap is one thing for a handcrafted soapmaker, and a very different thing for a commercial soap manufacturer.

For a soapmaker, milling or hand milling soap is rebatching.  You take soap you've already made, grate it up, add some liquid, heat it until the two have uniformly combined, add whatever extras you're going to put in, and pour it into molds. 

Personally, I've never seen the sense in making soap twice, but rebatching has its uses.  Its greatest asset is that you can add certain ingredients without exposing them to the chemical reaction between the lye and the oils, or the heat that the reaction generates.  Milk added to rebatched soap will not discolor it.  Rose petals will retain their color instead of turning brown and ugly.  Essential oils (eucalyptus, for example) whose fragrance would otherwise be evaporated by the heat during saponification will be unharmed and delightful to the nose.  And you can pour rebatched soap into individual molds that would be difficult or impossible to use with standard cold process soap.

(Rebatching is also a technique for salvaging a failed or improperly formulated batch of soap, but I'm not even going to touch that.  If it's bad soap, dispose of it properly.)

Commercially milled soap is an entirely different matter.  Briefly, french or triple milling is a manufacturing process that involves extracting the moisturising, skin-softening glycerin that's naturally in the soap, and drying the soap into pellets.  Inexpensive chemicals are usually added to make up for the loss of the glycerin, and the pellets are then passed several times through a rolling mill, producing a paste that can be compacted into nice hard bars.  The extracted glycerin is much more profitable to the manufacturer when used in lotions, creams, and other cosmetic products. (And if you have any doubts, check this out!)

In essence, the notion that triple milled soap is somehow better or of higher quality than soap that's milled twice or -- oh my god! -- a soap that is NOT EVEN MILLED ONCE is simply advertising spin.  A process that adds to the manufacturer's bottom line and significantly decreases the benefits to the consumer is touted as one that increases it.

It's . . . what was that phrase that caused such a flap during the 2008 Presidential campaign . . . ?

Also, check out our December 2009 update, Milling soap part II.