I previously created an Instructable that explained how to create a blue stain from black beans, but did you know you can also make a red stain by adding the correct mordant?

I used a step stool made from birch to demonstrate this process.

You can go back to my Black Bean Blue tutorial to review the process and to see the differences with each project. However, I will give full instructions for this project as well.

Supplies

Black beans (From the Latin section of the grocery, it makes a difference, more info in a later step.)
Water
Calcium Chloride a.k.a. Pickle Crips Granules
Citric Acid
Tartaric Acid
Large pot or bowl
Paint brush
Water based wax clear coat

Step 1: The Beans

To get the pigment from the beans is really quite simple. Get a large bowl or pot and put the beans in. Then fill up with water about an inch or so above the beans. Then just let them soak. Stir the beans every now and then to release the pigment from the beans.

Though, there are some tips to have the best results:

1. The first soak of beans will give you the darkest pigment. So be mindful of how big your project is and how much stain you will need. That will impact how many bags of beans you use.

2. The second soak will yield a weaker purpleish-brown that can work but not as dark.

3. If you want to get the pigment out a little faster, I found that gentle heat on the stove releases it.

4. My project required 5 cups or 1183 mL of the dye. This should help give you an idea of how much you may need for your project.

Step 2: Adding the Mordants to Turn the Stain Red

During the process of figuring out which type of mordant would yield the blue I wanted for my desk, I also discovered which mordants to use to yield red. There are three mordants that are required to make a vivid red: calcium chloride, citric acid, and tartaric acid.

My project needed:

5 cups or 1183 mL of black bean dye

1 tsp. or 5 g of Tartaric Acid

3 tbsp. or 44 g of Citric Acid

2 tbsp. or 30 g of Calcium Chloride

When mixing the 3 mordants into the dye I gently heat the dye to make certain that the mordants are completely dissolved. There is no need to bring it to a boil or create steam, just enough to make certain everything is dissolved.

The fun part is that while adding the mordants you can see the chemical reaction occur. The blue instantly becomes a bright red! As seen in the photos for this step.

Safety notes: While calcium chloride is used for making pickles, citric acid is used in canning, and tartaric acid is used in brewing beer (it puts in them realm of safer chemicals), they still require smart handling. Such as, keep out of reach of pets and children. Don’t get it in your eyes, etc.

Step 3: The Staining Process Part 1

Staining the wood is a simple process, just get a natural bristle paint brush and start slopping it on. I apply the mixture until the wood has that wet sheen to it. I let the sheen dry up before I apply the next layer. The wood doesn’t have to be completely dry just not shiny. Keep adding stain until you get the desired depth of colour you want for your project.

The first image of the stool is what it looked like before I began applying the stain. The second image of the stool is how dark red the stool became after applying the 2 cups of stain.

From the 5 cups of total stain I made I used about 3 cups or 710 mL to stain this stool. I used 2 cups of unmixed stain (see next step) and set 1 cup aside for the next step.

Step 4: The Staining Process Part 2

I like to use a clear water based wax when finishing my naturally stained furniture. I mix in some of the dye with the wax, because I find that this helps with preventing fading from UV light and from applying multiple layers of wax.

I took the last cup of stain I had and mixed it in with an equal amount of wax. This thins out the wax so multiple thin layers will need to be applied. Allow some drying time between each layer of wax. Since each layer is pretty thin it doesn’t take to long to dry.

As each layer of pigmented wax is applied the colour will darken, so keep that in mind for your project. I wanted a very dark red for my stool so I applied all of my wax mixture.

The first two pictures show the stool before the pigmented wax was applied and the last picture shows the completely waxed project.

Step 5: Tips and Discoveries

During the process of teaching myself about making this stain (dye) I discovered a few things that you should know so your project is a success.

1. There is a difference in the colour you get from varieties of black beans. The two varieties I tried are what I am terming Latin Variety and Asian Variety.

A. The Latin Variety is what I used to stain my desk. You can see the colour in the first picture. Once oxidised it turns from that purplish colour to that beautiful blue. This is the common variety you find in every grocery store.

B. The Asian Variety can be seen in the second picture. It has an inky-blue colour but once it oxidises on the wood it turns very purple. These are the variety you can buy from your local Asian grocery.

C. Even though I used the same mordant (calcium chloride) in both bean dyes, they yielded different colours.

2. Different types of wood could change the hue of the dye.

A. All woods are going to have their own pH and chemistry which could effect the hue of the dye. It is a good idea to test your dye on a piece of wood of the same type as your project.

B. Oxidisation is a big part of the process. Though the dye may look different in the pot it will change during the drying process.

C. Once the unused portion of the dye turns brown in the jar, it no longer stains blue. So you need to use it right away. It doesn’t even store in the fridge.

1. When making this stain red I noticed it did not change once the 3 mordants were added. So, it is important to put the calcium chloride, tartaric acid, and citric acid into your black bean dye before it turns brown.

2. The red version of this stain keeps longer and will remain red for days.

3. Be accepting of the variations that natural stains or dyes produce.

A. This is part of the fun.

4. You can find calcium chloride and citric acid in the canning sections of your grocery store. The tartaric acid can be purchased from your local home brewing shop.

5. Use a water based clear coating for the topcoat on your project.

A. Use your favourite if you have one.

B. A clear wax works really well with natural stains.

1. I mix my dye in with my wax and have always been pleased with the results.

2. Sometimes the wax curdles but I have not found that makes any difference.