Saturday, March 15, 2014

Black Walnut

The Black Walnut tree is native to North America.  One such tree grows on the edge of my neighbor's pasture.  Another grows in a vacant lot next door to my son's home.  I have been fortunate to be able to harvest walnuts from both trees.  While the nut is noted for its flavor, the green hull of  the nut can be used for dyeing.  When ripe, the nuts fall from the tree, the green hull loosens from the nut and can be easily peeled off.

My first exploration in dyeing with walnut hulls was autumn of 2009 when the hulls were freshly picked up from the ground.  Peeling the hulls from the nut, I put them in the dye-pot, covered with water, and let simmer for about an hour, then let it cool down.  The liquid was a deep brown.  After soaking in tap water for about 20 minutes, I immersed the yarn in the dye-pot and allowed it to simmer for about an hour.
Wool yarn, Black Walnuts

Black Walnut sample mordant card

In autumn of 2013, while visiting my son's family, I gathered a large pail full of black walnuts from the neighboring tree.  When I returned home with my stash, I had no time to get to the dyeing, so I left the hulls on the nuts and filled the bucket with tap water from our well, covering the nuts.  The bucket sat on the back patio all winter, freezing and thawing several times.  By spring the liquid in the pail was a dark espresso brown.  This liquid I poured off into one of my large dye pots, and I covered the walnuts in the pail with a fresh batch of water to see if I could coax even more color from those hulls.

The local fiber guild was having a meeting, so I gathered up my dye stuff and loaded the dye pot with the walnut liquor in the back of my truck.  I had a couple of skeins of mink yarn I had purchased the month before at a fiber retreat.  The mink yarn happened to be white...probably bleached to remove the natural color, and I thought it would be beautiful a deep espresso brown!  I would throw the mink, as well as a skein of recycled cashmere, a skein of my hand-spun merino/baby alpaca/angora, and a handful of alpaca fiber into the dye-pot.  A fiber friend had brought some mohair yarn and fleece, as well as some angora to add to the pot.  None of our fibers had been pre-mordanted.  The walnut hulls are rich in tannin and no mordant is necessary for the color to stay.  However, using mordants can shift the color to slightly different shades.

We soaked our fibers in tap water for about 20 minutes prior to putting them in the dye-bath.  Then we brought the temperature to a simmer and allowed the fiber to simmer for almost two hours.

While in the pot, the fibers appeared to have taken on that dark espresso brown we wanted, but we were surprised to see that when we pulled the fiber from the pot and squeezed the liquid out, the fibers were still only a medium-light brown.  The mink and wool were a taupe shade, while the mohair was taupe with a reddish hue.  The angora was a light shade of gray.  The dye bath was still rich with that deep espresso brown, so I don't believe we had put too much fiber in for the amount of dye matter.  Perhaps the difference in color,from what I had achieved in 2009, was due to the fact that these hulls were not used fresh.  I had also put one of my mordant sample cards in the dye-bath and that gave us a good indication of what other shades of brown we might achieve using mordants.
Mink on left, recycled cashmere center right, mohair on right.
Mohair fiber after 1st time in walnut dye-bath.
Angora fiber after 1st time in walnut dye-bath.
Black Walnut sample mordant card - 2014

Seeing the sample mordant card, we all agreed that the dark brown with the iron mordant was stunning! There was still plenty, PLENTY of color in the dye-bath but we had run out of time for the day.  I would take it up tomorrow, re-dye these fibers using some iron mordant and see if we could get a deeper shade of brown.

Next day:   I divided the dye into two pots, setting one aside and adding 1/4 tsp. of iron salts to the other.  The mohair, angora, and alpaca fiber went into this one and simmered for about 2 more hours.  The addition of the iron definitely gave us a deeper shade of brown on the mohair and alpaca, and a darker gray on the angora.  I decided to go ahead and add 1/4 tsp. of iron to the other half of the dye liquor and simmer the skeins in that pot.

Here were the final results:
Black Walnut dyeing - 2014

Fiber: top left, alpaca; top center, angora; right, mohair.  Skeins: bottom left, merino/baby alpaca/angora blend; 2 skeins mink; recycled cashmere bottom center; mohair center of picture.

Note:  comparing the results from 2009 using the fresh hulls and 2014 using hulls that had soaked in a pail of water all winter, it appears that using the fresh hulls will yeild darker browns.
Comparison of fresh hull dyeing to hulls that had soaked all winter.


  1. So interesting! These are lovely colours.

  2. Thank you. It seems there are so many surprises dyeing with plants. Our yarns looked almost black as we pulled them from the pot, so imagine how surprised we were to see so much of the color drain back into the pot as we squeezed them! I was pleased with the results after adding the iron.

  3. Very interesting, as always your posts about dyeing. My own walnut trees are still small and don't produce walnuts, so I have dyed only with dried hulls, and they don't give very dark color neither, and even iron didn't seem to darken the color very much:(

  4. Thank you, Leena! I always love reading your blog and consider you one of those master dyers that I look up to. I have not tried drying walnut hulls, but am sorry to hear they don't produce good color. One would think they would. I was just so surprised that since my hulls that sat in water all winter had produced an almost black liquid, the fiber simply did not take up the color the way my fiber dyed with fresh hulls did. It is a mystery to me.

  5. I had the opposite effect that you did. I had green walnut hulls soaking for a year, simmered for a few hours and let sit overnight to cool. I siphoned the hulls and dyed some bombyx silk to a deep cognac colour, again by simmering an hour or so and leaving it overnight. In another pot I had freshly gathered green hulls and did the same process but only got a light tan colour. The silk was pre-soaked for 24hours. Perhaps each year produces walnuts of different strengths?

  6. Thanks for sharing your experience dyeing with walnut hulls, Tabi. I am not sure what might contribute to the different strengths of color produced from one year to the next, especially if your hulls were all from the same tree, and the fiber you were dyeing was the same. Amounts of rain in a given year, soil conditions, etc. all may contribute in some way, but I wouldn't really know. In my case, I got thinking that the hulls I used were from two different trees, the first time from the tree next door, which the owners told me was a black walnut. The last time, the hulls were from a tree over 100 miles away in an empty lot. I thought it was a black walnut, but perhaps it was a different species. Identification of plant material has been a tricky thing for me...I wish I had studied botany in college.