Homemade Black Walnut Ink

Homemade Black Walnut Ink

Each fall I visit the same grove of black walnut trees in my neighborhood. I give thanks for the many gifts they provide and then begin my yearly ritual of foraging the fallen fruits from the ground, a first step in the process of making homemade black walnut ink. Walnuts create a rich, sepia-tone ink, which can be used to complement the monotone winter landscape. I find the medium ideal for capturing dried stalks, naked branches, and fallow fields. This year, I collected walnuts in the fall, dried the hulls, and then prepared my ink in late January. 


  • black walnut hulls (fill approximately 1/2 of your 5-gallon bucket)
  • a 5 gallon bucket for soaking the hulls
  • non-chlorinated water (enough to submerge the hulls in the bucket)
  • gloves to protect your hands from getting stained
  • a large non-reactive pot (a used stainless steel or enamel pot reserved for craft projects is ideal)
  • a strainer, 90 grade cheesecloth, and/or fine mesh bag
  • a funnel  (this wide mouth funnel with spout can be used on both wide or narrow jars)
  • glass quart jars to store the ink (a small flat jar is ideal for using the ink)
  • (optional) denatured alcohol or white vinegar to slow the onset of mold or mildew 

STEP 1:  FORAGE  Walnut is a deciduous tree that can grow over 100 feet tall and has a deeply furrowed, dark brown/grey, bark. It has long compound leaves with more than 11 leaflets and produces an abundance of nuts in the fall, which come encased in round hulls (some refer to this part of the walnut as a “husk”). These fruits grow 2-3 inches in diameter and turn bright green before falling onto the ground. Once on the ground they age, turn dark brown, and eventually fragment and expose the familiar walnut shell within ... that is, if a squirrel doesn’t snatch it up first!

The brown hulls are used to make the ink. This part of the fruit contains a juice that will easily stain to the touch, so wear gloves to protect your hands and put on some old clothes before you get started. There are two options for harvesting the nuts: 1) you can collect them when they are green and let them age in a bucket or on a drying rack at home for a few weeks or 2) you can wait and collect them from the ground after they've already naturally turned.

STEP 2:  SOAK  Once you have a bucket of brown walnut hulls, separate out any nuts that you may have collected in the process.* Next, submerge the hulls in non-chlorinated water (a plate and stone work well to keep the hulls under water).  Finally, let the hulls soak at least 18 hours. 

*Past years I tossed the nuts into my yard for the squirrels, but next fall I plan to deliver my walnuts to  Acornucopia Project, an Asheville based business that accepts nut deposits in exchange for credit towards nut-products.

STEP 3:  SIMMER  The goal of simmering your now sepia-tone stained water is to reduce it until it takes on the consistency of a thin syrup, slightly thicker than water.  So, after your walnut hulls have soaked for over 18 hours, strain the water into a large pot, and simmer on low for 8-12 hours. Expect to reduce the water by at least two-thirds. During this phase, I try to keep the hulls out of the water to avoid sediment dropping to the bottom of the pan and burning, however, if you are up for frequent stirring you can simmer the water with added hulls to potentially intensify the color. Be sure to keep an eye on your ink during the simmer process, the water can evaporate quickly!  I use an electric burner outside because of the sharp scent, but you can use your stove top if the smell doesn’t bother you. A used crock pot works well too, when set to low with the lid off.

STEP 4:  STRAIN  Once reduced to the appropriate thickness, it is time to strain remaining sediment out of your ink.  I use a sequence of strainers, beginning with a large screen strainer and ending with a fine cheesecloth. If you have the patience, a coffee filter does a thorough job.

Once your ink is strained, pour it into a quart jar for storage, as well as, one or more small 2oz jars for easy use. To slow eventual mildew or mold from forming, you can add 1 tbsp of denatured alcohol (such as rubbing or isopropyl) per liter of ink.  Another option is to add a cup of white vinegar during the simmering stage. 

A few notes to mention...

  • If you are allergic to nuts, check in with your doctor before using or making walnut ink.
  • Walnut ink is not waterproof or water resistant so it can be easily cleaned off of a non-porous surface, such as glass, but it will stain fabrics and skin
  • Do not discard the walnut hulls in your garden. Walnuts contain a chemical called juglone, which has herbicidal properties.
  • The commercial walnut ink, sold in most art supply stores, is not made from walnuts because it is perishable. I, however, have had the same bottle for 2 years with no sign of mildew or mold. If you keep it in the refrigerator you can significantly slow the rot.  
  • Walnut ink is acidic, so size your paper with 1:40 rabbit skin glue or a similar ground. 


Comments 3

Carol on

This is very helpful! However, I’m actually trying to dye my skin, to use the final product sort of like henna. I mixed up a batch last autumn, well before finding this article, and I use chlorinated water. I haven’t boiled down the strained walnut-hull water that’s been in the back of my fridge for a few months, so that might be why it’s not dying my skin either…

Any thoughts?

bparks on

Could you send answer to my email address? This is the first blog I’ve been on and will be totally sad if I can’t figure out how to find it and any answer you might send. Thank you.

Questions: There has been 2 solid days of rain. When I went back to neighbor’s yard to gather up the walnut husks left by the squirrels they all have some degree of mold. Prior to the rain they had none.

I am wondering what I should use to “de-mold” the husks. The squirrels have kindly broke them all open and ate the nuts so I am left with husks on shells. I’m planning on hand washing them all to get the mold off but it seems as if there will still be hidden mold that I can’t see. Will it be killed during the boiling stage? Or do I need to somehow clean it ALL off before starting.

Thank you.

Rebecca harden on

Wonderful. I’ve often wondered how to do. Thank you

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