Making a soap is easy and all you need are just oil and what makes it reach saponification, the Sodium Hydroxide (NaOH) or the Lye Crystals.
Sodium Hydroxide or Lye is very caustic, it is a toxic material that can burn anything when in contact. That is the reason why it has to disolve in water or any liquid before it is mixed with your oil materials to make soap.
You can not just mix water and Lye crystal because it can make a volcano effect, and the way to mix them together is to pour the lye crystal slowly into the water and wait for it to cool down before you mix it with your oil.
One good thing about mixing oil and lye solution is that, the oil change the composition of the lye into something that is non harmful, it becomes salt and when it goes through saponification it becomes what we use or called soap.
Saponification is the process where the lye solution (NaOH+H2O = salt) helps the oil mixtures achieve its trace state or the right consistency until it gets hard. (NaOH +H2O becomes exothermic or it heats up) that is why we have to wait until it cools down to 110-130 before mixing it with your warm preheated oil.
It is very hard to find 100% lye crystals in the market because of its toxicity, fortunately I found one at Lowe’s at the plumbing section. Be sure that it says 100% lye before purchasing it and using it to your soap making. Most of the drain opener or cleaners out in the market has different chemical mixture so never ever use that to make soap.
Make sure to use safety protective gears when handling lye crystal, use goggles to protect your eyes and wear mask so you will inhale the fumes it produces, the latex gloves is good to protect you hand and arms in case it gets in contact with your skin.
Always have the vinegar ready in case it gets in contact with your skin, lye is alkaline and vinegar is acidic so it neutralizes the alkalinity of the lye and after that rinse well with water.