INGREDIENTS:
Three bars of Fels Naptha (Top Foods $1.59 per bar)
Washing Soda (Sodium Carbonate).
Borax Powder
Grate or chop up 3 bars of Fels Naptha. This has been around as a laundry bar for over 100 years now.
Melt on stove in 54 cups of water. This is the longest part but still only takes about 40 minutes.
Once melted add 4 1/2 cups of Borax powder. I paid about $4.50 for this 4lb 12 oz box.
Add 4 1/2 cups of Washing Soda (not baking soda). This is sodium carbonate. I bought this 50 lb bag for $19.00 nearly 3 years ago and still have lots of it left. You can find this at many pool supply places. It has a higher PH and gives your clothing a good cleaning.
Here I have it added to the Fels Naptha soap mixture. It dissolves in about 5 minutes. Make sure to stir it really good.
I had my husband transfer the mixture into our 22 gallon container we've been using. Now add 235 cups of water. Yes, 235 cups of water. We have a line on our big, black pot we used to melt this all together in that is 55 cups so we only have to fill a little over 4 times. Maybe use a milk jug as that holds 16 cups. Hopefully, you have something larger. Stir with a stick or something large several times a day for the next 12 hours or so or it will gel up.
We bought this 55 gallon barrel at an Ocean Spray cranberry factory for $3 last year. I asked my husband if he could configure it to hold our soap. We already took some out as you will see below but it looks like we will get nearly 3 batches in here. So, I guess I will be making another batch next week if I don't have the baby by then. 
Here are some of our gallon milk jugs filled with the soap from the barrel in the garage. It makes it very convenient for many months to come. The clothes wash wonderfully in this and smell so good. We've had no complaints about using this formula so far and the savings is phenomenal. We used to go through all 18 gallons in about 9 months. Now we are going through it pretty quick with all of the kids.
You can use as little as 1/4 cup of this detergent. We use a full cup though as we have kids playing on the farm and Matthew working with chickens, etc...
