I want to make 50% citric acid

I want to make a 50% citric acid solution, from food grade citric acid crystals, I'm sure Ive seen instruction on how to do this in Jim's book " MMMS for the third millenium", but cant find this information now. Can any one tell me how to mix this up or where in his book I cant find out how to do this.

It's easy, Insite. Two choices -
1. do it by weight - weigh your water (down to nearest .1 gram) and weigh your citric acid (same) - they should be the same.

This is also one place you can do it by volume, since water and citric acid are so close in weight.
2. Take a measure of water (say 1/2 cup) and the same measure of citric acid packed down. Combine

Citric acid is a bit like brown sugar, you need to use it packed.

I usually will place on the stove on very low heat long enough to melt the citric acid (stirring) - (glass or ceramic pan, with plastic or wood utensil)

Pam