Cochineal insects are soft-bodied, flat, oval-shaped scale insects, native to tropical and subtropical South America and Mexico. They live on cacti, feeding on the plant’s moisture and nutrients. The deep crimson dye is produced by the females and their babies (nymphs) to deter predation by other insects, as they cannot fly, and they remain immobile while feeding.
For commercial production of carmine dye, cochineal bugs are farmed for three months, then collected at ninety days old. According to one description:
“The insects are carefully brushed from the cacti… and placed into bags. The bags are taken to the production plant and there, the insects are then killed by immersion in hot water or by exposure to sunlight, steam or the heat of an oven. It is to be noted that the variance in appearance of commercial cochineal is caused by the different methods used during this process. It takes about 70,000 insects to make one pound (454 gm) of cochineal. The body of one cochineal is said to contain between 18-20% of carminic acid.
The part of the insect that contains the most carmine is the abdomen that houses the fertilized eggs of the cochineal. Once dried, a process begins whereby the abdomens and fertilized eggs are separated from the rest of the anatomical parts. These are then ground into a powder and cooked to extract the maximum amount of color. This cooked solution is filtered and put through special processes that cause all carmine particles to precipitate to the bottom of the cooking container. The liquid is removed and the bottom of the container is left with pure carmine.”
During production, various other substances can be used, including stannous chloride, citric acid, borax, or gelatin.
Image: Madeleine Ball (Flickr)