A fancy name to explain how mixing a fat (oil) with a base (lye) will create soap! Or you could say that soap is a salt of a fatty acid if you wanted to sound like a smarty pants. Basically, saponification is what happens when you mix oils and lye together to create soap. There is a lot more official science stuff to saponification, but I don't want to sound pretentious so I'll just say this: to make a batch of soap, you have to have oil and lye. The lye goes into the oil and they mix together, change their molecular structure, and become soap! It's a very special and beautiful process, one that probably kept humanity alive much longer than it would have if someone had never started mass producing it.
Some like it hot... Okay sorry, I'll be serious. This means that you mix your oils and lye together over a heat source (think witch's cauldron) and cook your soap until the oils and lye saponify. After an hour or two, you will have soap! Do you like instant gratification? Then this is the soap-making process for you! Just kidding. You still need to let your soap sit for a few weeks to cure, but the cooking soap over a bubbling pot is pretty fun, and one nice thing about hot-processing soap is that you can choose what oil you superfat with. Worth it!
Most of us from Generation X think of this soap as the transparent round bars of soap you could buy at the health food store. You know, the ones that were always lightly colored and scented with honeysuckle or cucumber? My kids think of glycerin soap as melt and pour that you can get at craft stores. For once, both generations are correct! This isn't the best summary of what glycerin soap is, but it gives you a basic rundown. To get a clear soap (aka glycerin soap) you still need oil and lye, but if you want to make it clear then you need to add solvents to the soap, usually in the form of alcohol, sugar, and glycerin. I usually make my own glycerin soap base to make my melt and pour embeds for the tops of my cold process soaps. I love doing it; there is something pretty cool about watching the soap become translucent.
A syndet bar is slang for synthetic detergent bar. A lot of us use these and love them. Think Dove or that awesome solid shampoo bar that you spent $25 bucks on and you're not sure how it can bubble so amazingly. The thing about detergent bars is that they aren't technically soap. They clean like soap but don't do the oil and lye dance. There are lots of great reasons to make and use them. For example, I am formulating a dish-washing paste that is basically a solid detergent block for people who have hard water and want to lose the plastic bottles. Traditional soap and hard water don’t do great things for dishes. Remember all those commercials in the 80s about having guests over only to discover water spots on your dishes? Well, if you think that’s bad, try using a true soap bar to wash your dishes. You will have ditched the plastic but you won’t be able to show your face in polite society cause you’ll have water spots. I mean, I suppose you could install a water softener but where’s the fun in that.
Oil infusions are awesome for soap-making. For example, a turmeric infusion is a great natural way to get a bright yellow color in soap. There are lots of reasons to make herbal oil infusions to use in your soap, but the main one that most soapmakers use them for is a source of natural colorants.
These forms of colorants are almost entirely made in labs now. They used to be mined (they still are but not for cosmetic use) and way back in the day it wasn't uncommon for people to put makeup or powders on their face that caused toxic heavy metal poisoning. Synthetic colorants are nature identical but created without the harmful heavy metals so it's a win-win all around. As a side note, I also make sure to only purchase micas and oxides from suppliers that certify and guarantee that their products are cruelty-free.
This refers to the way in which you go about saponification. Basically, you'll mix your oils and lye together at room temperature and let everything sit for 24 hours. The end result... Soap! Cold process requires the soap to "cure" (basically harden up) for 4 to 8 weeks, otherwise it will be mushy and won't last very long when you use it, so you have to be patient. I.e. stop stealing bars off the curing rack to test it out! Yeesh!
Most of you probably wouldn't know this, but talking about curing soap with other soapmakers is sort of like talking politics at Thanksgiving. It's a toss-up as to how it will play out. I've seen some ugly stuff go down when this topic comes up. I'll spare you the multitude of opinions on this and just let you know how I feel about it. Curing soap means that you let all the liquid you used to dissolve the lye evaporate so that the soap gets hard. (This isn't 3rd grade, stop being vulgar.) If you don't let the soap cure long enough (the average length of time is about 4 weeks), then your soap will be mushy and won't last. (FYI, this also happens if you leave your soap sitting in water. Don't do that.) If you let your soap sit on the curing racks and age like a cheap wine, then you'll get a fantastic bar of soap that should last you at least two to three weeks, provided you don't store it like a degenerate between uses.
Sodium Hydroxide (NaOH): Used to make bar soap. Also known as lye or caustic soda.
Potassium Hydroxide (KOH): Used to make liquid soap. Also known as lye or potash.
Since I have your attention, I'd like to bust a myth that plagues all of us in the soap-making industry. All soap has lye in it. That's right, all soap has lye in it. Now, before you panic, the lye has gone through a chemical change and is no longer active once it becomes a soap molecule. Don't worry, you won't get burned if you use soap that has lye in it. There is a myth out there that some soap doesn't have lye in it. This is like the myth that daddy-longlegs are deadly but their fangs can't penetrate human skin. It’s false. Some soap makers will say that their soap is made with saponified oils to avoid having to deal with explaining the saponification process, but now you know the truth and you don't even need Mythbusters!
Believe it or not, this isn't an insult. Superfat is the extra oil left in the soap that doesn't go through the saponification process. Every soapmaker worth their bubbles will be sure to include a superfat into their soap recipe to aid in extra moisturizing and also make sure that every lye molecule gets turned into soap.
P.S. If you ever want to impress a soap maker, compliment their soap's superfat.
This is just a nicer way of saying soap sweat. Just kidding. Actually, glycerin dew is the little drops of liquid that will form on glycerin heavy soaps if they are stored in humid places. Glycerin is a natural humectant, which means it draws water out of the air to itself. This can also happen with salt soap too. It's nothing to worry about, but if you don't want your soap to develop the dew/sweat/glisten (whatever you'd like to call it) then you can store your soap in cool dry areas or wrap it in plastic to avoid this happening.
Sometimes people also call soap dough, soap clay. I think soap dough might be the coolest thing. Did you know that if you make cold process soap and put it in an airtight container to saponify, it will stay pliable like playdoh! You will be able to treat it like clay and mold things with it. When you are done, leave it exposed to air and it will harden up into regular soap consistency. Pretty awesome!