This is a partial list of things used in making soap. Those marked with an * are suggested as the required minimum. Like any hobby, the list will get longer - it always does.
* Lye. Sodium Hydroxide, NaOH, for bar soap; Potassium Hydroxide, KOH, for liquid soap.
* Carrier oils and fats (Coconut oil, Crisco, olive oil, shea butter, etc.)
* Distilled water. (Available at most supermarkets)
* Stainless steel (or enamel) stockpot(s) (4 to 30 qt. depending on size of your recipe). For safety, oil plus lye solution should be less than ½ the pot height.
* Large stainless steel spoon for stirring.
* Stick Blender.
* Lye mixing container (2 qt. vinyl drink container will work quite well).
* Soap molds. Can be homemade from PVC pipe or wood. If using wood molds, you'll need freezer paper to line the mold.
* Thermometer (a candy thermometer will work).
* An accurate weighing scale. The reasonably priced scale advertised on this page would be a good choice with its 11 pound capacity and resolution of 0.1 oz or 1 gm.
* Running water & vinegar to neutralize accidental lye splashes.
FIRST, flush area where lye was splashed thououghly with running water.
Then, neutralize remaining lye with vinegar.
* Goggles or some form of eye protection.
Medium to large rubber spatula to help empty soap into molds.
Stainless steel spatula to scrape sides of pot (for DBHP hot process).
Essential oils and/or Fragrance oils. (Warning, collecting these can be addicting.)
Coloring agents. (Ditto)
A few things that were probably left off the list.