Earthballs contain a yellow-brown dye, but also a large and annoying amount of tiny, black spores. So I set out to find out if the spores contain any dye or if they could just be discarded.
A couple of years ago, I dyed a lot of yarn with earthballs. The color turned out a nice yellowish brown, but the yarn was simply full of spores that continued to drizzle out, both when winding the yarn into skeins and when knitting with it.
The drizzling pores were obviously annoying, but I also started wondering if the spores are even safe to breathe? It’s usually said that earthballs are “moderately toxic”.
In their book “Färgsvampar & svampfärgning” (Dye mushrooms and dyeing), Lundmark & Marklund label earthballs “good” dye mushrooms, so it would be a pity to give up on earthballs just because of the spore problem. Lundmark & Marklund mention that earthballs contain the dyes badion A, norbadion A, and sclerocitrin.
Sclerocitrin is also described in the research paper “Unusual Pulvinic Acid Dimers from the Common Fungi Scleroderma citrinum (Common Earthball) and Chalciporous piperatus (Peppery Bolete), Angewandte Chemie International Edition, 2004, 43, 1883-1886 by Winner et al. They show that the “brilliant yellow” dye sclerocitrin is found in “remarkable amounts” in earthballs. As the title says, sclerocitrin is also found in peppery boletes. I haven’t looked for it, but a mental note has been made.
Earthballs have a dark or black spore mass inside, surrounded by a relatively thin outer wall. I decided on a small experiment in order to see if the spores contain any dye. If not, it would make sense to just leave them in the forest.
I used as small amount of earthballs for my experiment, gathered during the fall of 2016 and dried until use (2016 was not a good mushroom year, so not many earthballs were to be found).
Separating the spore mass from the mushroom’s outer wall was incredibly difficult. The parts were completely stuck together in the dry mushrooms, but in the end, I had 23 g of out walls and 10-11 g of spores. I soaked both overnight, the outer walls simply by adding water. The spores were stuck together in stone hard lumps that I separated by grinding them in my mortar. The spores repel water, I solved that by wetting them in denatured alcohol, then adding water.
The next day, I boiled the two dye baths and filtered the spore bath through a coffee filter. It took very long for the liquid to run through, that’s always the case when filtering a solution with many tiny particles. I then dyed a 10-gram alum mordanted test skein (Fenris 100% wool) in each bath, and got the result below – almost the same color from the two.
The top skein of yarn in the picture is dyed with the outer walls, the bottom one with the pores. I had hoped to find that the pores didn’t dye, but clearly that’s not the case. In principle, it’s not surprising, though, to find that sclerocitrin and the other pigments are distributed throughout the mushroom. The dark color of the spores is not caused by a pigment that acts as a dye.
In conclusion, all parts of the earthball contains dye, and discarding the pores would mean discarding a lot of good dye. So the best method for earthball dyeing would be using the entire mushroom, wetting the spores with alcohol, and then investing the time required to filter the entire dye bath before any wool is added.