I used to make laundry soap for myself all the time but got out of the habit after I moved. Pity. Now that I'm especially concerned about limiting my plastic consumption, I've decided I'd get back into it. So here's what I did:
I gathered up the equipment
1. small pot
2. large plastic bucket for mixing
3. wooden spoon
4. paring knife (cheese grater would probably work better if I happened to own one)
5. measuring cup
7. Washing soda
8. Kirk's bar soap
9. Old empty soda bottle
11. Fragrant oil
Pare or grate soap into a bowl or measuring cup. One bar of Kirk's soap is equal to about 1 cup of soap shavings.
Dissolve one cup of soap shavings in two cups of boiling water. Now you have liquid soap!
Pour two gallons of water into a bucket. I used one with a cover in case I felt like storing my finished product in it.
Add one cup of borax, one cup of washing soda and the liquid soap. Mix them with the wooden spoon.
What you have now is lovely, slimy, viscous gel that personally I had to play with. If you have it, you can add fragrant oil to the mixture. I added lavender and tea tree oil.
Using a funnel (or in my case an old soda bottle cut in half to form a funnel) pour the mixture into old detergent bottles.
That's it! Now you're all done except for feeling very smug about your super green domestic skills.