Blood

In detail

Blood is a protein soil, and proteins denature with heat: the molecule unfolds and binds irreversibly to the fibre, which is why a blood stain rinsed in hot water becomes a blood stain you now own. The carpet trade's instruction is to rinse the spot quickly with cool water, and the same logic governs fabric. Cold and fast beats hot and thorough, and this is one of the few places in cleaning where acting immediately changes the outcome rather than merely making it easier. Beyond temperature the standard spot procedure applies — blot with a dry white absorbent cloth, work any solution in gently from the edges of the spill towards the centre rather than rubbing, and keep going while the stain is still transferring to the cloth. Enzymatic products act on this class of soil by cutting the protein into fragments small enough to rinse away, which is a different mechanism from either detergency or bleaching. The one thing worth flagging is that the carpet trade names an ammonia solution among its options for this stain, and ammonia is the substance most implicated in domestic chlorine gas incidents when it meets a bleach-based product on the same surface.

What works

• Acetic acid (vinegar) is effective against Blood Supported

  Named by the wool body for blood on wool: undiluted white vinegar, dabbed, followed by cold water.

• Enzymatic cleaner is effective against Blood Supported

Why

• Blood is explained by Protein denaturation

Hacks and claims involving this

• Hot water for a blood stain Does not work
• A stain method that works on cotton works on anything Does not work