Lye is dangerous stuff. If you’ve ever thought about making soap (or lutefisk, ew) but have been too scared, allow me to assuage your fears. If lye were a Ghostly Gondolier who haunts Venice, I would be the Scooby-Doo team who shows up to reveal that the boatman is really just an loser who wants to steal valuable medallions. By way of a clumsy metaphor, I’m trying to say that understanding what makes lye so scary can be a great way to face your fears.
Ever since I was little I’ve loved making “lotion potions.” My cousin and I would hunt through my grandma’s drawers, pulling out every hotel-sized lotion, soap and shampoo we could find. We’d grate the soap, mix up the lotions and sometimes even add a spritz of my grandma’s perfume – Eternity, which my grandpa still buys for her every year on her birthday – to make our creations smell good. Now that I’m all grown up (and have my own drawers full of stuff), I still love mixing up potions. There’s just something magic about taking whatever I can find and turning it into something that can clean, heal or beautify.
Soap is no exception. I started making my own soap last year for Christmas. It seemed easy enough and I wanted to give my brothers shaving brushes and soap. I ended up with 15 extra bars that I gave to my grandmas. They loved how soft it made their hands and so I, being the queen of dry skin all winter long, started making it for myself.
The History of Soap
Many many years ago, there was a mountain near Rome called Mount Sapo. In honor of the goddess Athena, the people from neighboring towns would carry goats and sheep to the top of the hill and burn them atop a sacrificial fire. As the animal fat melted and mixed with the alkaline ash, soap formed and was later carried to the stream below by rain. The women in the towns did their laundry in this stream, finding that their clothes got cleaner at Mount Sapo than anywhere else.
Oatmeal and Lavender Soap
|5.5 oz||coconut oil||Coconut oil gives your soap moisture, big bubbles and a harder bar. I buy mine at Trader Joe’s or Costco, but it’s pretty trendy right now so you can find it just about anywhere.|
|8 oz||olive oil||Olive oil gives a dense creamy lather and a soft bar.|
|4 oz||water||Water is used to dissolve the lye. It will evaporate as the bar sets.|
|1.97 oz||lye||You already know what lye does, but you might not know where to buy it. Check the drain-unclogging chemicals sold at at Lowe’s or Home Depot. As long as it’s 100% sodium hydroxide, you’re good to go.|
|1/4 t||honey||Honey is a natural humectant and will keep your skin soft. It won’t dissolve into your soap, so don’t add too much or you’ll end up with honey bubbles and oozy soap.|
|5 drops||lavender essential oil||Lavender oil is calming and helps keep itching from dry skin at a minimum.|
|1 t||shea butter||Shea butter is incredibly moisturizing. If you don’t want to buy any, you can add a teaspoon of any oil or butter.|
|1 T||oats||Oatmeal soothes dry skin and scrubs off dead skin. Grind it up fine (I used my magic bullet because I’m fancy) so that it doesn’t clog your drain.|
Soap is the metallic salt of a fatty acid. What in the world does that mean? Well, in chemistry, salt isn’t just the white stuff that always hangs with the pepper, it’s any product that comes from neutralizing an acid and a base. Let’s take kitchen salt (sodium chloride) as an example. When you combine hydrochloric acid (HCl) with sodium hydroxide (NaOH), you get sodium chloride (NaCl) and water.
HCl + NaOH –> NaCl + H2O
This is particularly cool because hydrochloric acid is crazy acidic (it’s the stuff that your stomach uses to break down food) and sodium hydroxide is suuuuper alkaline (remember the scene in Fight Club when Brad Pitt burns that ugly hole in Edward Norton’s hand? That’s lye AKA sodium hydroxide) which means achtung, baby! Put them together, though, and you get two completely safe and consumable substances.
Making soap – or saponification, if you’re savvy – is pretty much the same thing. Add lye to an oil and you get a salt that we call soap! More specifically, you combine a trigylceride with lye and end up with soap and gylcerine.
C3H5 COOR COOR COOR + 3 NaOH + (H2O) –> 3NaCOOR + C3H3 OH OH OH
You already know what lye is, but what’s about triglycerides? As it turns out, all the oils we’re familiar with are different types of triglycerides. If you look at the formula for triglyceride, you’ll notice there are some R’s up in there. Those R’s stand for fatty acid radicals, three of which are combined to create a single type of oil. Olive oil, for example, is made up of two oleic acid radicals and one palmitic acid radical. Because of their chemical makeup, different oils and fats have specific properties that can be helpful or harmful in soap making. We’ll talk more about this when we get to the recipe.
The glycerin that’s a byproduct of the reaction is one of the best reasons to make your own soap. Glycerin is a humectant (a thing that keeps moist things moist) and makes your skin soft and moisturized. Often, store-bought soaps have been stripped of most of their glycerin, which is then sold to be used in more expensive bath products.