I've posted my recipe for Cloth Diaper Detergent, but never considered to post the version for laundry detergent. Silly me :)
They are basically the same, except that the regular detergent has soap in it :)
What soaps can you use?
From my understanding, most any bar soap will do. I think most people try to choose something that's easy on the skin.
Fels Naptha (Love this stuff)
Ivory (I think you can even find flakes of this, which would be handy)
So what's the recipe?
Basically it's this:
1 cup washing soda
1 cup borax
1/2 cup of oxiclean
1 bar of soap, finely grated
There are tricks to grating it. The best one I've heard is to chop it up (food processor can help here), lay it out on some cookie sheets to dry for a day or so, and then chop it up again (again, food processor, big help!) Be careful not to push your processor too hard (don't rush it!).
Now, I said that the above recipe is basically the recipe. I don't like leftovers and I don't like having to do things over and over again, so I like to make large batches. It's a little more work at the time, but a lot less work over time :D
Here's the full recipe:
3 Boxes Arm & Hammer Washing Soda (55 oz each)
2 Boxes 20 Mule Team Borax (76 oz each)
1 Large Tub OxiClean (96 oz)
24 Bars of Soap, finely grated
Depending on what soap you get and how you buy it (bulk, discount store, etc.) you can make a full batch of this for around $60 and it will last a VERY long time.
I've found that getting large buckets to mix this up makes it SUPER easy! Layer all of your ingredients into one (or more) buckets. Pour from one bucket to the next, and repeat until it's mixed to your satisfaction. That's it!
This recipe has a higher yield than the CD detergent, so yo may need more than 2 buckets to mix back and forth.
How do I use it?
I liked to use 2 tablespoons per load of laundry. My husband has a fairly dirty job and I have messy kids *cough*daughter*cough*
If I'm doing a cold wash, I have a jar that I keep close by that I can put my scoops into, add some hot water and help dissolve it a little before throwing it in the wash. It will work without doing that, but I like to.
**I'd like to make a note about the borax used in this recipe. A recent article by EWG cautions the use of borax for cleaning in the home noting that toddlers and young children face special risks from hand-to-mouth transfer of carpet or crack and crevice, dust or spray borax treatments. I would recommend not using borax as a general home cleaner - any cleaner (aside from pure water) used for these purposes will leave a residue. I feel comfortable using the minuscule amount in the detergent. It is not used on open surfaces and is washed out during the rinse cycle.
You can read a bit more on this debate here - there are some great points of view in the comments http://www.theecofriendlyfamily.com/2009/08/laundry-detergent.html