Why Cold Water Matters
Blood is a protein-based stain, and heat causes proteins to coagulate and bind permanently with fabric fibers. This is the same chemical reaction that turns a raw egg white opaque when you cook it. Using hot water on a blood stain essentially cooks the protein into the fabric, making removal extremely difficult or impossible.
Always use cold water when rinsing, soaking, or laundering blood-stained items. This single rule is the most important thing to remember and is the number one mistake people make when trying to remove blood stains at home.
Removing Fresh Blood Stains
Fresh blood stains are relatively easy to remove if you act quickly. Hold the stained fabric under cold running water, allowing the stream to push the blood out from the back of the fabric. For most fresh stains on cotton or polyester, cold water alone will remove the majority of the stain within minutes.
- Rinse immediately under cold running water from the back side of the fabric
- Apply hydrogen peroxide directly to any remaining discoloration
- Rub gently with your fingers or a soft cloth
- Repeat the peroxide application until the stain is gone
- Launder in cold water with enzyme-based detergent
If hydrogen peroxide is not available, your own saliva contains enzymes that break down blood proteins. While it may sound unusual, applying saliva to a small fresh blood stain is a tried-and-true method used by quilters and seamstresses for generations.
Removing Dried Blood Stains
Dried blood stains require more aggressive treatment. Soak the garment in cold water with a tablespoon of salt for several hours or overnight. The salt helps break the bond between the dried blood and the fabric fibers. After soaking, apply an enzyme-based stain remover and work it into the stain with a brush.
For stubborn dried stains, make a paste of unseasoned meat tenderizer and cold water. Meat tenderizer contains papain or bromelain enzymes that specifically break down protein structures. Apply the paste, let it sit for 30 minutes, then rinse and launder.
Special Fabric Considerations
On white cotton sheets and pillowcases, hydrogen peroxide is safe and highly effective. On colored fabrics, test peroxide on a hidden area first as it can cause bleaching. For silk, use only cold water and a gentle enzyme soak. Wool responds well to cold salt water soaking. Mattresses should be treated with a spray bottle of hydrogen peroxide and then blotted dry. For large or valuable items, professional treatment ensures complete removal without damage.