Real solar dyeing with food coloring & vinegar

This is my first experiment with solar dyeing. Most of the books and websites that discuss “solar dyeing” are really talking about sun tea-like steeping in large glass jars. That process does not produce enough heat to fully set most dyes. You need temperatures of 180–190°F / 82–88°C to set most dyes, especially acid dyes for protein fibers and many natural plant and insect dyes for cellulose and protein fibers.

Adapted from The Sunny Side of Cooking: Solar cooking and other ecologically friendly cooking methods for the 21st century:

I want to use solar cookers to replace stovetop steaming, oven steaming and crockpot dyeing methods. As I mentioned in post a few days ago, solar panel cookers have cooking temperatures of 200–300°F / 93–149°C. Because I used food coloring as the dye and white distilled vinegar as the mordant, I used a three liter solar cooking roaster and my CooKit™ panel cooker.

I decided to dye a thrift store skein of white wool. It weighs 2.35 oz/67 g. I presoaked it in a stainless steel bowl for 45 minutes in a solution of water and a couple of cups of vinegar. I spun it out in a salad spinner, also from a thrift store, so that the fiber would be damp, but not wet. I spread out a piece of newspaper and a layer of white paper towels. This turned out to be inadequate to catch all the water in the dye solutions. I have some old bath towels I use for wet felting, but they are forest green. I will buy some white towels the next time I go to a thrift store (I want to be able to see the dye mess).

I made up four dye solutions, the first one in a glass jar, the rest in specially-made dye squeeze bottles with tight caps and small orifices:

  • 25 drops each regular green and neon blue + 1 ½ cups of water (my main dye solution)
  • 10 drops neon purple + ¼ cup water
  • 10 drops neon blue (plain blue) + ¼ cup water
  • 10 drops regular green (green + a little blue) + ¼ cup water

I could have also used drink mixes like Kool-Aid, which also contain their own mordant, citric acid.

I wanted to use the main aquamarine color for most of the skein. I first tried using an eye dropper to apply the main dye color, but it seemed too slow so I switched to dip dyeing sections of the skein into the jar and squeezing it out (while wearing rubber gloves). I then layed the skein on the towels. I applied the three accent colors to the white areas left on the skein. I finally added some yellow stripes directly out of a food coloring bottle on top of a couple of green areas. I had just enough squeeze bottle dye, but twice as much of the main dye solution as I needed, so I screwed on a lid, applied a label that says, “food coloring dye” and put it in the refrigerator.

I put ¼ cup of water in the bottom of the roaster and then a metal trivet. I didn’t want the metal to affect the final yarn colors so I added a layer of parchment paper on top. I gently squeezed out excess moisture from the skein, being careful not to let colors bleed into one another too much. I folded the skein in two and layed it in the roaster with the two purple areas together (to prevent color bleeding into adjacent aquamarine areas).

I set up the CooKit™ on my driveway just like I did the other day to cook rice at 12:30 p.m. The books and websites I had consulted beforehand said to steam hand painted skeins for 45 minutes. Because there were a few clouds on a mostly sunny day, I left the pot in the cooker for two hours. Solar cookers require adding a heat up time to the steaming time.

I removed the pot, brought it upstairs and left it to sit four hours. Then I rinsed the yarn in a soap solution. I spun out the water in the salad spinner. The rinse water was almost completely clear, with just a trace of yellow. I hung up the skein to dry overnight. I am very happy with the colors.

The purple turned out really well. I had heard that purple food coloring easily separates into its constituent red and blue pigments because their uptake times differ, but I think my cold application method and steaming method (as opposed to immersion dyeing) prevented too much color separation. I liked the purple so much that I went online and bought some specialty AmeriColor™ food coloring gels in shades of fuchsia/magenta/maroon, royal purple/violet/neon purple and turquoise/jade greens from the Layer Cake Shop.

Now I really want to build a large solar panel cooker so I can dye skeins without lying sections on top of each other, dye larger amounts of fiber/yarn at once, do solar immersion dyeing with cochineal, and dye with non-food safe dyes like Procion MX for cotton. I need to do some research on my options. I have some ideas about panel materials.


Questions to consider when choosing a solar cooker Part II

Me with my Global Sun Oven™ on my front balcony a few years ago.

Adapted from The Sunny Side of Cooking: Solar cooking and other ecologically friendly cooking methods for the 21st century:

Do you live in a sunny, arid climate? Any solar cooker will work for you. Most of the American West, including high latitude locations like Montana, fit this description.

Do you live in a humid or cloudy climate? This includes sunny, humid places like Florida. Solar ovens with multiple reflectors like the Global Sun Oven™ perform best in hazy or partly cloudy conditions.

Do you live in a windy climate? Choose a sturdy box cooker with few or no reflectors made of plastic, wood or metal, such as the Sport™ solar cooker . It is possible to use multiple-reflector cookers in windy climates (I do), but you’ll have to firmly attach the cooker with bungee cords or tent stakes. Avoid parabolic reflectors unless you can build a very sturdy one; they are particularly vulnerable to wind because they tend to be lightweight, plus the parabolic dish catches wind like an umbrella turned upside down.

Part I
Part III
Part IV
Part V
Part VI



Fireless cooking refried beans

We eat a lot of refried beans here in Arizona, whether we are vegan or not.

Part III of the The Sunny Side of Cooking is called “The sustainable kitchen.” The book’s subtitle is Solar cooking and other ecologically friendly cooking methods for the 21st century. This section is about how to cook with the least amount of energy when the sun doesn’t shine. Together with solar cooking, these other cooking methods create a year-round sustainable cooking system for all climates.

A fireless cooker is an insulated box that retains the heat of cooking without additional heat. For hundreds of years, European peasants stuffed wooden boxes with hay. Often, the boxes would serve double duty as benches and have elaborate carvings and decorations. During World War I and II, hay boxes helped people survive fuel rationing. Also called insulated box cooking, these cookers were known as “victory ovens” that complemented victory gardens. Fireless cooking saves one-third to 95% of the fuel that would otherwise be needed to cook food.

I use a Coleman cooler with old blanket pieces as my fireless cooker. A cardboard box can work just as well.

Fireless cooking has two parts: simmering time on a stovetop or solar cooker and fireless cooker time. The simmering time heats the food to boiling and begins the cooking process. The fireless cooker retains the heat to allow cooking to continue. And once the pot is tucked into the fireless cooker, you can walk away. You can leave the house without worrying about the food burning or overcooking. The heat gradually dissipates. Solar cooker and slow cooker/crockpot recipes are easily adapted to fireless cooking, as are stovetop and microwave recipes.

I have found that at 7,000 feet elevation, using a pressure cooker in a fireless cooker requires roughly the same simmering time and fireless cooker time as a regular pot with a tight-fitting lid does at sea level. I cooked the unsoaked pinto beans for only 15 minutes on high pressure on the stove and two hours in the Coleman cooler. They were mashable with a fork

After I remove the pot from the cooler I leave the cooler open to allow cooking moisture and odors to evaporate before I put the blankets back into the cooler for storage.

See my post on making sourdough wraps/tortillas here.

See my post on combining solar cooking with fireless cooking here.

Wild Bread: Handbaked sourdough artisan breads in your own kitchen.