“Come and start to make homemade soap. No special tools needed. Just get your ingredients from us and use our recipes. Its easy.” The sales person called enthusiastically. While her statements might be true for some people it would not be true for a great many others. It would depend on high tech their kitchens were. There are two tools which are essential to consistently making good soap: a thermometer and scales that are accurate to the gram or to 0.05 of an ounce.
You need a thermometer when you make homemade soap to accurately measure the temperatures when you add your ingredients for consistently successful batches. If you mix the lye into too cool an oil/fat mix then the solid fats and oils can go solid in a false trace. Or your soap may go grainy when the temperatures are too high or too low. If the lye or oils were too hot you might find chunks forming in your bowl while mixing. Successful soapmakers suggest this cannot be fixed and the mixture must be thrown out. So it is important you get a cooking thermometer that measures in the 60 to 140 degree Fahrenheit (100 – 200 degree Celcius) range. This is lower than most meat thermometers so make sure you can get the lower ranges as well as the higher ones.
An accurate set of scales is the second most important tool. It should measure small ranges. If you make homemade soap in small quantities (anything under 3 poiunds or 1.5 kg of oil) you need to have scales that will measure accurately to the gram or to 0.05 of the ounce as the lye quantity is very important. If your scales are not accurate enough you can end up with too much lye and it will leave you with little stings and a slimy bar if you persist in using the soap. Too little lye and you end up with fat that hasn’t been saponified. Under some conditions this soap can develop a bad smell or grow some mold on it. So do make sure you have the right tools so you can get the proportions right when you make homemade soap.