Soil and Stain Chemistry
Soil and Stain Chemistry
Soil and Stain Chemistry tests matching a stain's chemistry to a safe treatment, with pH and fiber compatibility as the first constraints.
Core rules and concepts
- Soils are particulate, oily, protein, tannin, dye, or mineral. Identify before choosing a product.
- pH matters: wool prefers mild acid to neutral; cellulosics tolerate mild alkali but risk browning; always rinse.
- Oxidizers (peroxide, percarbonate, bleach) remove color and can damage dyes and wool. Use only with proven colorfastness.
- Reducing agents (bisulfite, thiosulfate) and acids (oxalic acid for rust) reverse some oxidized stains.
- Protein stains (blood, milk, egg) respond to cool water and enzyme or mild alkaline treatment, never hot water.
- Tannins (coffee, tea, wine) are acid stains; use an acid tannin spotter and blot, don't scrub.
- Urine is acidic with salts; neutralize and deodorize. Ink needs solvent; rust needs oxalic acid.
Worked example
A coffee stain on wool is blotted, treated with a mild acidic tannin spotter, dwelled briefly, rinsed, and dried with airflow. Hot water and high-alkaline cleaner are avoided because they can set the stain and damage wool.
Traps
Hot water on protein; bleach on wool; over-wetting; and using alkaline products on tannin stains.