OK, to rebatch that soap, the first thing you need to figure out how much of each ingredient you actually used. That means you need a digital scale. You put your measuring cup on the scale and hit tare(power) button long enough to get 0 grams. Then you add 3 cups of the same type of oil. Write down this amount exactly. Pour the oil back into the bottle, but don't wash the cup just yet. Place a dry cup on the scale, and hit tare again. Add 3/4 c of the lye that you used. Write this amount down exactly also. Return that to the bottle.
Go to soapcalc.net, or the reputable
lye calculator of your choice. Click on the grams button at the top. Select your oil, and click the grams button. Type in the amount of oil you used. Hit calculate recipe.(Leave the 5% superfat and the 38% lye ratio alone for now.) Click view or print recipe. That will show you the amount of NaOH you should have used at the top. Olive oil has a NaOH SAP value of 0.134, which means that for every gram of olive oil, it takes 0.134 grams of NaOH to saponify it. So, take the amount of grams of NaOH that is in excess of that amount, divide by 0.134, and that resulting number is the amount in grams of olive oil you need to add back to the pot. (Someone with actual math ability and far more experience than me PLEASE check this process??)
Now, put a pair of gloves on, and get a stainless steel grater, and grate all the soap into either a crock pot, or a stainless steel pot of some sort. Weigh out the missing olive oil(into the already dirty cup). Cook on slow until you get a melted sort of transluscentish paste. This will be irregular in texture and color. It theoretically should not zap you when tested. Mash and smash the soap(use caution, this is HOT.) back into the mold and allow to cool. Should be ready to cut as soon as you consider it cool, but press on it first, and if not firm enough, give it a bit more time.
