14 October 2013

Adventures with Walnut Ink

Eight years ago I moved into a house with a walnut tree in the front yard. Some years there are lots of walnuts - some years not so much. But, every year I pick them up off the lawn (they would usually end up in the yard waste bin), sweep up the casings that the squirrels shuck off and find the nuts buried in the strangest places all over my yard. 

Then, about 5 years ago, a student gave me some walnut ink which I loved and since then wondered if I could make my own. Every year I would let that crucial span of time go by and before I knew it the nuts were gone and I would think..."next year"...

This year I finally did it! And, here is my adventure.

This is the walnut tree in my front yard

The walnuts grow on the tree in these green casings. It is those casings that create the ink. When the nut falls and the casing splits and becomes exposed to air they start to turn black. When put in water the color starts leaching out and turns the water to dye, stain, or ink.

Some techniques I saw on the internet involved soaking the whole walnut - nut and all. But, that is not necessary since it is the casings that create the ink. I happen to have very industrious squirrels who do a lot of the shucking for me.

Every morning, for about a week and a half, I would go outside with a little hand broom and sweep up the casings that the squirrels left around my yard, on the fence, in the dirt and sometimes right on my porch. I also gathered a few fallen nuts and did some shucking myself with a small knife. I think the smaller you get the casing pieces the better. Be sure to wear gloves since your hands will get stained touching the casings.

I put them into a pot of water that I kept outside and let them soak. As I found more casings I would add them to the pot. I thought I would have time to cook them after about 3 days but the days got away from me. I found that they were fine sitting outside in the pot as long as I stirred it every once in a while and replenished the water if it got low. At one point it started attracting bugs so I covered it for a while, and it also bubbled for a few days (fermenting???). But, it didn't get too smelly and it didn't get moldy.

After about 11 days of soaking (I have heard of people only soaking them for 1-3 days) I had time to cook it. I added a little more fresh water, brought the pot to a boil on the stove and then simmered it for 3 hours

After three hours it was dinner time but I realized I wanted to cook it down a bit more. So, I took the pot off the heat and put it outside until the next day. As you can tell it is not a delicate process. It seems you can let the stew sit and pick up where you left off later!

The next day I started cooking again and this time decided to do some dying along the way. As I was simmering I put in a few pieces of cloth, one at a time, to see what the results would be. Be sure to wet the cloth first with warm water so that it will more willingly accept the dye.

This was an old linen napkin. It looks a little dirty here (below) but I think after I wash it it will be a nice brown. I also tried out a piece of cotton with embroidery on it and a piece of printed silk.

Finally, the walnut stew started reducing and at this point I would dip a small paint brush in every once in a while and test it on a piece of paper. I have read since that you should strain it after about 3 hours of cooking and then put the liquid back on heat to reduce it. I did a lot of the reducing with the casings still in there. I might alter that next time.

I strained the walnut mush stew...

and came out with this lovely bowl of walnut ink!

What I am not showing you here is what happened between the picture above and the picture below (don't DIY instructions always leave something out?) Well, I'm going spill the dirty parts: I divided the liquid from the bowl (above) into two jars and a small bottle and covered them while they were still warm. Well, naturally after about 2 days they developed these lovely spots of mold on top. Darn! Back to the internet for some research and realized that I should put some ethyl alcohol in the mixture. So, I scraped the mold off the top, boiled, simmered and retrained the mixture again, let it cool and then added 5-10% ethyl alcohol. In doing so I reduced my ink quite a bit and ended up with this:

It is a beautiful brown ink.

I think I put in a bit too much ethyl alcohol so it bleeds a bit on paper but I think I can evaporate some of that off.

As you can see I took very scientific notes throughout the process recording cooking times and providing ink samples. The top center brush mark (above) is the final color after adding the ethyl alcohol. I can now alter that color by adding more water or reducing it more, if I want.

This was an adventure in trial and error and playful experimentation. I had fun with it and hope to do it again next year.

Please let me know if you have anything to add from your own adventures with walnut ink as I am sure I have much to learn.

p.s. one of the things I loved most about this was how totally "green" it was. The squirrels got the nuts, I got the casings and after cooking and straining I mixed them into the earth under the tree to nourish him for next year. 


  1. Very cool! I can't wait to try it out. Will be soaking my batch of walnuts from Wednesday on. Thanks for posting and will lyk how it turns out! :-)))

  2. this is awesome, what a great post and how long do you think it will keep?

    1. The walnut ink that my student gave to me about 5 years is still good - no mold or bad smell - and it has been un-refrigerated the entire time. But, she purchased it so not sure what kind of additive is in it. We will see!