Laundry liquid

I stopped using commercial washing powder a number of years ago because I tend to wash my washing at 30degrees which seems to be too cold to fully dissolve some powders, leaving a whitish residue on dark items. So for years I have been using commercial non-bio laundry liquid. A friend of mine told me that she makes her own, so when I ran out of my usual, I went to the internet and found a recipe that I adapted. It works pretty well, I have washed three loads with it and it seems to do the job for a fraction of the price of commercial.

To make 4L of concentrated laundry liquid

Ingredients

Grating soap in food processor

100g of soap (Castille is recommended, avoid soaps made with palm oil as it's production damages rain forests in Asia) (grate the soap, I used the grating disc on the food processor)
4 L of boiling water
2 cups washing soda (sodium carbonate) (available in cleaning aisle of supermarket)
1 cup baking soda (bread soda/ sodium bicarbonate)
1 cup borax (optional, is a brightener)

Method
In a pot melt the grated soap with 1L of boiling water, in the meantime,
in a plastic bucket (not aluminum as it reacts with washing soda), dissolve the washing soda, baking soda and borax in 3L of boiling water, use a wooden spoon to stir.
Once the soap is melted and the sodas dissolved, add the soap solution to the bucket. stir it up with the wooden spoon and then use a stick blender to properly mix it. Don't worry, the two solutions will separate again, in fact, they never stay mixed. Once the mixture has cooled down, transfer it into bottles. (Washed out milk bottles will do)
To use, shake it up till it is homogenised, and use 50-100ml per wash depending on soilage.

Blended soap solution in bucket

One of 4 Litres of laundry liquid

Costings:
Bar of soap < €1
Washing soda, 2 cups < 50c
Baking soda, 1 cup <50c
4L boiling water < €1
Total for 4 L < €3