So I'm deviating from my theme of food recipes to post something slightly different. This weekend, I made soap! And the reason it was so awesome is because I learned every detail of this chemical reaction in advanced organic chemistry last fall. If you combine fatty acids (from animal fats, vegetable shortening or oils) with a strong base like sodium hydroxide, the esters of the fatty acids will be cleaved to produce an alcohol and a carboxylate salt (aka soap) by nucleophilic acyl subsitution!

Ok I'll stop geeking out now.
So more background details: This past weekend our friends "cutlet" and "ham" from the Toscano Farm were "harvested." Among the many cuts of meat my father brought home was a ridiculous amount of fat. I mean, like half of each pig was made of fat I swear to god. So I decided, in the spirit of sustainable farming, I would try to make soap from this fat instead of throwing it away. Note to my vegetarian readers: You can easily do this recipe WITHOUT using animal fat and it will still work! Just substitute vegetable shortening.
Home-made Soap
Ingredients:
-Pig tallow
-Lavender oil
-Fresh Lavender buds from the yard
-Petroleum/vaseline
-Ice cold water
-100% sodium hydroxide aka lye (I bought this in the form of Roebic's crystal drain opener, available at Lowe's or Ace Hardware. Before you get sketched out by using drain cleaner, just know it is 100% NaOH and is the same as specialty lye products that can be bought online. Also, make sure you do use this brand because the MSDS sheet does verify that it's 100% NaOH and some other drain cleaners do not contain the pure form of this chemical)

First I had to render the animal fat. This was a slightly smelly but easy process that just involved putting fats in a pot on the stove, putting some water in the bottom of the pot, then boiling the fat until the "gristle" floated to the top. This website is helpful to guide you through.
After rendering it, wait for fat to congeal again, then measure it's weight as accurately as possible with a kitchen scale (in pounds).
Next, type your fat's weight into this handy-dandy soap calculator to figure out the ratio of lye/water to add to it.
Next, you'll have to dissolve the lye in ice water according to the ratio from the soap calc. This gets a little tricky because it's an exothermic (heat-producing) reaction that can potentially be dangerous! Wear gloves and eye protection if you have it! First, make an ice-water bath in a large bowl. Drop some salt in there too to lower the temperature. In a GLASS bowl/container, measure out the pre-determined mass of ice cold water and put this in the ice bath, then add the predetermined mass of lye and stir. Things might get steamy!
After making the lye solution, pour it into another bowl that contains your animal fat (in congealed form) and start stirring....keep stirring...keep stirring...I stirred for 2 hours. This might have been extreme but I read online you should stir until it the mixture is thick enough for you to be able to "trace" the path of your spoon in the mixture. At this point, I also added lavender oil and lavender blossoms/leaves from a plant in my yard. You can add any fragrance you like, even oats to give it some texture!

Next, pour the mixture into a mold (I used a glass brownie tray) that has been coated in a layer of petroleum/vaseline. Leave mixture there overnight to set before trying to cut it. It may need to set for 3 days or more after cutting.
Here's how mine turned out!!!


