In this episode of Plants to Dye for – season 2, we're dyeing with cochineal. Cochineal dye comes from parasitic insects (Dactylopius coccus) that live on the prickly pear (or nopol) cactus and are native to Mexico, Central and South America and the Canary Islands. They live in colonies and obtain moisture and nutrients from the cactus. The females produce carminic acid, which they use to deter insect predators. A natural red dye is derived from the carminic acid, which can be pushed to the shades of red with cream of tartar, or fuschia with soda ash.
The dye has been used to color food and to dye fiber for centuries. Farmers brush the cochineal off the cactus leaves to harvest, and then dry the insects.
I purchased cochineal from Dharma Trading right here in the Bay Area.
They import dried insects that are sustainably farmed in Peru, a major exporter of the product. Dharma recommends using 20% Weight of Fabric (WOF) for cochineal. This value may differ per vendor, depending on the intensity of carminic acid in the insects (for example, Maiwa recommends 3-8% WOF for a medium shade using their product). Cochineal dye is very sensitive to the pH, so distilled water is recommended. The dye also performs best when the dye bath is kept between 180 and 200° F.
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Dried cochineal insects
The weight of fabric for this project is 385 grams (or about 13 ounces).This includes four white cotton dish towels, and one dish towel that has already been dyed with madder, which I plan to use for an over-dye experiment. Twenty percent WOF for 385 grams of fabric is 77 grams of cochineal, or 2.7 ounces. I have 2 ounces of cochineal – close enough. Fabric should be scoured and mordanted. We used a gallnut mordant, followed by a bath of 15% WOF alum and 2% WOF soda ash as a brightener. See Scouring your Fabric (Soaking Method), Mordanting Fabric (Oak Gallnut), and Mordanting Fabric (Alum Brightener).
Outdoor studio with basic equipment
For this project you need basic dye equipment, and a well-ventilated workspace. You need a soaking pot, a dye pot, a heat source, and a candy thermometer to keep the dye bath at a consistent temperature. You need a grinder, a small pan or can, strainers, and jars in which to store the decanted liquor and the dye bath. For safety, wear a face mask when working with fine powders, and rubber gloves when working with soda ash.
Add to a pan, and cover with 3 inches of distilled water.
Bring to a boil, and then turn off heat. Let soak overnight. (Note that some instructions say to simmer for 30 minutes, but I didn’t do that.)
The next day, pour the extracted liquor into a jar, filtering out the pulp.
Add the pulp back to the pan.
Repeat steps 2-5, two more times.
First, grind the dried cochineal insects to release the carminic acid. I’m using my marble cutting board and rolling pin, metate style (but am protecting the marble with layers of freezer paper). You could also use a dedicated coffee mill, or small food processor, one that is not used to process food.
Makeshift metate and supplies for grinding the cochineal
Ground cochineal powder
Add the ground powder to a small pan (I’m using a can that once held enchilada sauce). Cover the powder with three inches of distilled water. Cochineal is sensitive to pH, so distilled water is recommended because its pH is neutral. Tap water may be more acidic.
Use distilled water when working with cochineal
Stir together the cochineal powder and distilled water
Bring the mixture to a boil, and then turn off heat. Let soak overnight. The resulting liquor is deep red and glossy. The next day, pour the extracted liquor into a jar, filtering out the pulp. Add the pulp back to the pan, and repeat two more times to continue extracting dye pigment.
The extracted liquor is glossy red
Strain the extracted liquor through a sieve into a jar, and reuse the pulp
Note that you can continue extracting color several more times, although the color becomes weaker. The number of times depends on the concentration of carminic acid. I extracted dye a total of six times over the course of a week. You can see that the resulting dyestuff becomes lighter and lighter. Compare the jar on the left (extractions 1 and 2) with the jar on the right (extraction 6). I could have continued, but have limited storage space, so chose to stop with six extractions.
Extractions 1-6, from left to right
I'm using extractions 1-3 for this dye project, and am storing extractions 4-6 in separate jars, so it doesn’t dilute the dye from the first three extractions.
Extractions 1-3
According to Maiwa, some dyers keep the remaining pulp in a jar of water for several weeks and use it for future dyebaths. I’m storing my pulp in the freezer for future experiments.
Allow to cool in dye bath for maximum color absorption.
Rinse and hang to dry.
Presoak prepared fabric before dyeing
Add water to the soaking pot and presoak the prepared fabric for at least an hour (or overnight). This helps ensure that the fiber soaks up the dye evenly. Stir occasionally.
Combine extracted dye and distilled water
Pour the cochineal liquor into a pan of distilled water. I started with a gallon, which is plenty for the fabric to move around the pan when stirred. Add more water as needed. Simmer your dyestuff for an hour keeping the temperature between 180 and 200° F.
Simmer the dye bath, keeping the temperature within range
Add the wet dish towels. Stir to loosen the fabric. Add additional water if needed. Simmer the fabric for an hour, keeping the temperature between 180 and 200° F. Continue to stir periodically for even dyeing, turning fabric frequently while simmering. Surprisingly, I did not have much trouble controlling the temperature of the cochineal dye bath, compared with the madder project (see Dye Project: Madder Root).
Let the dye bath cool
Turn off the heat and let the pan cool. Leave the dish towels in the dye bath for as long as you want. I covered the pot with foil, and soaked overnight for saturated color.
Rinse fabric until the water runs clear
Squeeze out water
Squeeze out excess dye from the dish towels into the dye bath. Rinse the dish towels in cool water until the water runs clear. The color was so saturated, that I used more water than usual to rinse. Run the dish towels through the washing machine’s rinse and spin cycles without soap.
Use the rinse/spin cycle a couple of times
Air dry the fabric
Let the towels air dry. In a couple of weeks, run the towels through the washing machine using Synthrapol and rinse. Include a piece of white cloth to test colorfastness. Air dry again.
Cotton dish towel dyed with cochineal (fuschia)
You can save and re-use the dye bath for lighter shades. Preserve the dye in glass jars to reuse in future projects. The color may be less intense but is still usable. Cochineal can be used in combination with other dyes, such as madder or logwood.
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