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Cold Process Soap Making with Lye: Answers to the 8 Most Common Questions About Using Lye


So, you're ready to learn how to make cold process soap. But making soap with lye... kinda scares you.

I had the same fears, friend! I literally thought I was going to burn the house down, so I put off making that first batch for ages. (Once I finally did it, though, I realized it wasn't that scary.)

If I had been more familiar with lye, and how to work with it, it would have gone a long way to helping me feel less nervous and more comfortable. So that's what I'm aiming to do here, for you, before you start your first batch.

Here the most common questions about lye use in soap making. If you have a question that isn't answered, please feel free to ask me by posting a comment on my Facebook page or emailing me.

What is lye?
Lye is a caustic that today is most often used as a drain opener (and is one of the key ingredients in Drano.)

Although it sounds like a horrible addition, it's a necessary ingredient for making handcrafted soap. It's used to saponify the oils, or chemical change them from oil into lovely soap.

When cold process soap is properly made, there won't be any lye left in your finished soap bars. 

Can you make cold process soap without lye?
No, it's not possible to make handmade soap without lye. But don't worry. So long as you're careful it's perfectly safe.

If you use bleach in your home safely, if you pump gas into your car safely, you can use lye safely. Lye isn't inherently more dangerous than other common caustics we use daily. It's just that you're unfamiliar with it, and unfamiliarity breeds nervousness.

As long as you follow proper soap-making safety guidelines you will be able to make soap without any problems.
 
If you're not comfortable using lye in your soap making right now, try the melt and pour method instead.  (Check out this article for more melt and pour soap info.) The "lye part" is already done for you. All left to do is melt the base down, add fun ingredients, and pour into the mold. Done!

What type of lye do I need? Is any brand OK?
You must only use 100% lye in your soap making. If the package does not specifically say 100% lye, or 100% sodium hydroxide (the chemical name for lye) you should not use it.

The most common brands you'll find locally are Roebic or Rooto.

Definitely don't use brands like Drano, etc. They contain lye but they also contain lots of other chemicals that are dangerous additions to your soap. 

Where can I buy it?
 Lye is sold at the hardware store next to the drain cleaners (another big reason why you must check the label for 100% lye, or 100% sodium hydroxide. You don't want to accidentally purchase the wrong product.)

Another great option is to get your lye directly from soap making suppliers online. This way you'll know you're getting the exact right product. It just takes some of the worry out of buying lye, especially for the new soap maker. And while you're shopping, you can order any oils, mold, and fragrances you may need too. :)

At my local store, they keep lye behind the counter and I have to show my ID before they'll sell it to me. What gives?
If you can't find 100% lye on the shelf at your local hardware store, ask if they have it behind the counter. And, if they do, be prepared to also show your ID.

Besides soap making, lye can be used in the manufacture of illicit drugs (chalk that one under who knew?)

Even if it's on the shelf, I always like to tell the cashier what I'm using it for. It saves me from those funny looks I get when I'm buying several canisters of the stuff and nothing else.

How did they make soap before you could buy lye at the store?
Our pioneer ancestors used to make their own caustic using wood ash and water, but it's a long and arduous process. And the end result can be of varying strength, so you never quite know exactly how much you need in your soap batch. Which is why some batches of soap from the bygone days where harsh enough to tan the skin off your body, and why old time lye soap got bad name.

 If you're curious, this article has some great info on how wood ash lye is made.

Can I make my own caustic then?  
Some hard core soap makers still create their own caustic like the pioneers did. So, if you really really want to make your own lye for your soap, you can. But there's no way to gauge just how strong your homemade caustic is, which can leave you with lye-heavy bars.

It's really much easier (and safer) to buy lye. I've made soap for years, and have never made my own lye. And, unless the apocalypse hits and I'm in desperate need of some soap, I never will make my own lye.
  
Yikes! The warnings on the canister look scary!
Yeah, they do. But try not to let them frighten you. Sure, lye is caustic and can be harmful if handled improperly but it's not anything to be scared of.

Have you ever used Drano on a slow drain? Then you've already worked with lye. And you did it with nary an incident.

You might be surprised to learn that olives and pretzels are given a lye-water bath. And we eat those!

So handle lye carefully, use precautions and common sense, but don't let the warnings stop you from making soap. Once you've got a batch or two under your belt, you'll feel much more comfortable and realize that working with lye safely isn't all that terrifying.

Still got soaping questions? Check out these articles too:

Soap Making Safely: The DOs and DON'Ts for Handling Lye

How To Make Cold Process Soap 

How To Safely Neutralize Lye and Handle Lye Spills

Not Ready for Lye? Oatmeal, Milk and Honey Soap - No Lye Recipe

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