Wow, it's been a year since I moved to Guelph. Crazy. (also means I should be 1/3 of the way through my PhD, but let us not think about that). Which also means it's been about a year since I first tried making laundry detergent! I am still going strong with it. I have lost track of batches, but I think this must be about my fourth - so that is pretty good going for a whole year's worth of laundry. It cost me about $5 for the Borax, about $5 for the washing soda, and less than a dollar per bar of soap that goes into the detergent. Even if you get the cheapo store-bought detergent, that's significant savings (I still have 3/4 of a box left of both Borax and washing soda). Money far better spent at the pub, if you ask me.
Anyway, I made another batch last night and just wanted to update to note that I may have solved the texture problem. It seems that adding more washing soda makes the finished product more lumpy and gelly. This is fine to a point, but sometimes it doesn't dissolve properly in the washer and leaves soap spots on my clothes. This time, I made the soap and stirred everytime I went by while it cooled. Then, a few hours later when it was set, I poured in some boiling water (about a cup, maybe?) and stirred that all up like crazy. This dissolved all the lumps and now, the next morning, the whole thing has not reset into lumps but remains a nice, even, liquidy texture. I think I will add this to the standard process.
My recipe at this point is:
Dissolve one bar grated Ivory soap in 6 cups boiling water. Stir till dissolved.
Add 1/2 cup Borax and one cup washing soda. Stir till dissolved.
Pour into giant bucket and add 6.25L (25 cups) HOT water. Stir.
Let cool, stirring as often as possible.
When cool, add 1 cup (ish) boiling water. Stir vigorously to break up any lumps.
Use 1/2 cup to one cup (I use one due to Guelph's horribly hard water) as liquid laundry detergent.