I got tired of hauling huge jugs of vinegar and pouring (should I say slopping) vinegar into my jars when I was dyeing. So I bought a 5 lb. jar of citric acid crystals and have been experimenting with amounts. The acid dye process works when you infuse the dye molecule into the wool fiber. This is a chemical process that is done with a mild acid like vinegar or citric acid, which creates a special chemical bond between the fiber and the dye color molecules.
Citric Acid is a bitter acid derived from citric fruits and it is used in everything from cosmetics to flavorings for food.
Citric acid is SO EASY to use I recommend switching immediately. It is more cost effective and has no mess at all. And I found that the dye water cleared much better than it does with vinegar.