Okay, well here is what I did. Keep in mind I am not an expert and most of the information here is just regurgitated from other threads on this site and a couple other places I poked around on the internet. But this is what I did and what I would do differently next time. Though my goal here was to make a laundry soap I was also trying use up the scraps, odds, failed soaps and experiments I’ve done. Most of the soaps that went into this were old soaps from my first year of soaping. If you are wanting a super well performing dedicated laundry soap as has been mentioned you are probably better off starting from scratch and making a CO soap base to work with. But here it is.
1. I came here and asked a couple questions. DeeAnna had some really good advice about not boiling it out but doing a re-batch to saponify the SF in the soap. I however did not follow this advice because my soaps were all full of junk. There were some with clays, big chunky pieces of oatmeal and whatever else I thought of trying in soaps. So I thought I should just boil them up to clean this stuff out. After I did my first boil however I realized I could have done both, by adding additional lye during the first boil. To do I should have / will in future calculate a general SAP value for my super fatted oils. In going over my notes these soap where either straight up Castiles and Bastiles so I am good with using the rounded SAP values DeeAnna posted above as .136 & .180. So almost all of these soaps were an 80% to 20% olive or RBO to CO my average comes to .145. So in my case I wound up using 750g of scraps. All of these soaps were done with soapcalc at the default setting of 5% SF. The 750g x .08 = 60g of SF in my scraps. 60g x .145 = 8.7g of NaOH to add to my first melt and boil to tidy up the SF. If you take into account that there are non-soap solids in my soaps (the clays, oats, sugars ect) and I made the NaOH calculation based on the weight of my scraps you may note that this is actually a little high since the weight of the additives in there too. Sine I am boiling it, it will come out and I’m not bothered by this. I will throw this NaOH into enough water to cover the soap and do a long first boil, maybe 40 minutes.
2. I collected up a bunch of my old soaps and dusted off the salad shooter. I’ve only got the one cutting insert for my shooter (thrift store score) but if you have another shredder or are doing it by hand the thinner the shreds the better. There is something about shredding soap that I find very zen. Even with the loud whirring of the shooter it is very calming. If I had to do this by hand I may not feel the same way.
3. The first boil is where I made a mistake. For some reason I was thinking that I was just supposed to boil the soap in a brine. This is not the case. When I did this the soap got to its melting point and then just hung out on top of the brine I had mixed and added to the pot first. The right way is to add just water let all the soap dissolve and then add the salt till the soap and now brine water decide they don’t much like each other and the soap separates from the brine. It makes sense when you think of it like the whole thing is called “salting out the soap” you’re salting the soap out of the water. Though I did it wrong the scrap soap did drop allot of the junk into the brine. After 20-30 minutes I started scooping the soap curds out with a slotted spoon into a strainer to cool down.
The soap being not entirely solid did press itself through the holes in the strainer (big holed spaghetti type not the screen type) and made short soap noodles which were kind of fun to shear off with my hand. It was around here when I realized that my strainer was pretty much a perfect fit for the pot I was using so I planned to throw it in the pot before the next boil and I could just let the soap cool and just lift it out when it was cool.
4. For the second boil after the soap had mostly cooled down I broke it up threw it back in the pot and covered it with fresh (non-salted) water. I did about equal parts by volume and melted it back down again. I placed a lid on the pot and told myself that I was being impatient and to make sure to sit there with it as covering the pot would cause the soapy solution to boil over and make a mess. I then saw something shiny, a squirrel or something with pretty buttons and let the soap boil over onto the stove causing a huge mess. After stirring the suds back down and reducing the heat I kept it at a low boil for about 20 minutes and started salting.
I didn’t measure the amount of salt I used but it just became apparent when the soap was lifting out of the brine. This time the soap curds were much cleaner looking than the first time through. It was getting late so I just let the soap cool down for an hour or so then lifted the strainer out of the brine and slipped a long spoon through the handle to hang the strainer over the brine and threw the whole thing in the fridge.
5. The next morning I took everything out of the fridge and popped the soap out of the strainer.
I then took a trip to Medford to stay with my aunt and uncle to show Soapcutter the ranch and let her help with the animals. It was a really nice trip and Soapcutter had a blast, got to ride a horse, quad and the tractor!
6. When I got back I cut up and shredded the mass of now cleaner soap. The shreds felt kind of damp still so I spread them out on a cookie sheet and put the fan on them. I turned the shreds whenever I passed through the room and they felt dry enough after a few hours but I went ahead and left them there with the fan on low over night.
7. The next day I looked at a few different laundry soap recipes and settled on by weight 50% soap shreds, 25% washing soda, and 25% equal parts borax and an oxy clone. I used the metal chopping blades in my food processor to grind and mix everything together. My processor could only handle about half of the soap I had at a time so I made two batches. Each batch got about 20 drops of Eos for scent.