Just three ingredients... olive oil, water, and... ... ... baking soda?!?!

[Saltynuts]

I was just watching soaping videos and I saw this one:



So, isn't banking soda fundamentally different from lye? Can it really make soap like that? If so, any thoughts on that type of soap?

Side question: why can soap from Turkey and China be made SO much less than they can make it? Big machines to mass produce it in those countries?

Thank you.

 

[Babyshoes]

I've always assumed that was a mis-translation. Another name for lye is caustic soda, which if very pure can also be used in food production.

As for your second question which I think is about the cost, I'd imagine it's to do with the cheap labour in those countries.

 

[The Efficacious Gentleman]

Cheap labour, cheap ingredients (buying in bulk and/or poor quality), and producing in bulk - time is the biggest cost and it doesn't take me much more time to make an 8kg batch than it does to make a 2kg batch

 

[ResolvableOwl]

I've always assumed that was a mis-translation.

If you ask me, it is much more likely that these bags say “caustic soda” than “baking soda”. (Snapshot from your video at 0:34, rotated so that the labels are easier readable).

But even if we assume for the moment that they used baking soda (sodium bicarbonate): this is HP, and in boiling water, bicarbonate will decompose to liberate carbon dioxide and convert into washing soda (sodium carbonate). This is a more aggressive base than baking soda (but still not as caustic as NaOH is).
So then, while technically baking soda is added, the active ingredient is washing soda.

However, washing soda is so cheap by itself that it makes no sense for a company to produce it rather than just buying it.

Another indication that this is indeed a nasty translation error (and/or a historical inaccuracy stemming from the times when NaOH wasn't easily accessible, and/or journalists copying from other journalists that have no clue, and/or PR to make the soapmaking process sound less scary to customers).

 

[TheGecko]

I was just watching soaping videos and I saw this one:

So, isn't banking soda fundamentally different from lye? Can it really make soap like that? If so, any thoughts on that type of soap?

Side question: why can soap from Turkey and China be made SO much less than they can make it? Big machines to mass produce it in those countries?

Translation error. It’s been tried before, but there are too few hydroxide ions produced when turning the soda into carbonate. You’re better off making your own Lye from hard wood ash and water.

Commercial soap is made the same way the world over…continuous process method. Palm Oil, Palm Kernel Oil, Coconut Oil and Tallow are the most common ingredients (go to the grocery store and read the labels). These fats come into the factories in tank cars…either by rail or truck. When you are purchasing that much product, you’re paying pennies on the pound.

A lot of the process is automated. Fats and steam are continuously fed in which separates the glycerin out and then lye is added to the fatty acids. The saponified soap is pumped into large flats that go into a freezer and once cooled, they are turned into noodles, milled, and extruded. Depending on the manufacture, the soap can be cut into simple bars and wrapped or the bars go into a press where they are shaped and stamped and then wrapped.

As an artisan cold-process soap maker, I could probably at best, produce a hundred bars a day. And by produce, I mean from start: from weighing, mixing, pouring into molds, saponification, unmolding, cutting, planing, beveling and stamping to finish: packing and labeling. Providing of course, that I already have soap in process. The actual making of a 100 bars would only take a couple of hours, but I generally leave it in the mold for a couple of days and then I cut it. Then I wait a week to plane, bevel and stamp. Then it has to cure for another five to six weeks, then I can package and label. So my day would be divided between these different process.

If I was a factory…I could fully process 100,000 bars easily in a single day. From weighing in fats into the Hydrolizer, to boxing it up and putting it on pallets and off to the warehouse to be shipped to distributors and then to your local store.

Right now, even as small as I am making four-10 bar loaves a week, using six oils/butters and including my labor, I can produce a plain bar of soap for a buck. The closest I get to ‘automation’ is that I master batch my oils and lye solution. If I can make a bar of soap for a buck in my kitchen, how much do you think it’s costing a commercial soap maker? Especially in countries that pay poverty wages?

 

[DeeAnna]

...Another name for lye is caustic soda...

This what many bar-soap makers assume is the meaning, but that's not exactly correct. The word "lye" means any strongly alkaline liquid solution. This includes the potassium hydroxide solution (aka caustic potash) used to make liquid soap as well as sodium hydroxide (aka caustic soda) and other strong alkalis.

The alkali in "lye" can be a hydroxide such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, etc., or it can be a carbonate such as sodium carbonate (washing soda) or potassium carbonate or even sodium bicarbonate. The problem with using a carbonate lye, especially bicarbonate, is that these alkalis require a lot more heat and/or time to force the saponification reaction to proceed than if you use a hydroxide lye.

Fire extinguishers that use baking soda are often recommended to fight grease fires in the kitchen. The baking soda mixes with the flaming grease and saponifies some of the hot grease into soap. The heat of the fire itself as well as the saponification reaction cause the baking soda to decompose and release carbon dioxide gas. The CO2 gas, and to a lesser extent the soap which doesn't burn like grease does, help to smother the flames.

A century or more ago, "lye" or "ley" was the water-based alkali you got when you leached ashes with water and got an impure alkali solution that was mostly potassium carbonate. This lye/ley could then be reacted with slaked lime to convert the carbonate alkali into a potassium hydroxide solution. Either of these alkali mixtures could be legitimately called "lye" or "ley" depending on what era you lived in.

Caustic soda is sodium hydroxide
Caustic potash is potassium hydroxide
Soda, as the word is used in industry, is sodium carbonate
Potash, again as the word is used in industry, is potassium carbonate