Cochineal is the female insect of Dactylopius coccus that colonize the prickly pear (nopal) cactus native to Mexico, Central and South America and the Canary Islands. Peru is currently the primary export country. This dye can be found in food, drugs and cosmetics. Cochineal has excellent light and washfastness and produces a powerful range of fuchsias, reds and purples. The dye is sensitive to pH and color changes can be achieved with different mordants and varying the pH of the dyebath. 

Cochineal is naturally a very concentrated dye. 3-8% WOF is all thats needed for a medium depth of shade. 

Mordanting: 

• Protein Fibers: use alum mordant at 15% WOF.
• Cellulose mordant with tannin at 8% WOF and then alum at 15%, or alum acetate at 8%.
• Adding cream of tartar at 6% WOF to the alum mordanting bath or the dyebath will shift the color more towards Christmas red.
• Adding iron at 2-4% WOF to either the mordanting bath or the dye bath will shift the color towards purple.

Dyeing: The color needs to be extracted from the dried insects before dyeing.

1. Gently grind the insects in a blender or use a mortar and pestle to crush them to a fine powder.
2. Place the powder into a saucepan and cover with 2 to 3 inches of water.
3. Boil for 30 minutes and then strain the liquid and set aside.
4. Place the cochineal pulp back in the saucepan and again cover with water and repeat step 2.
5. Add this decanting to the first decanting and repeat step 2 a couple more more times.
6. Properly dispose of the remaining pulp.
7. The combined decantings can now be used to make a dyebath. 

Cochineal is sensitive to pH. A rich red can be shifted to orange with the addition of an acid (vinegar, citric acid or other acid modifier) and to a deep fuschia with the addition of an alkaline (soda ash, baking soda or alkaline modifier). This sensitivity means the soaps used to wash your fibers can have a color effect on the dye if they are not pH neutral.