Aesculus hippocastanum, the horse chestnut, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is a large deciduous, synoecious tree. Also known as: horse-chestnut, buckeye, conker tree, or Spanish chestnut. Not to be confused with its' edible cousin the sweet chestnut.
We also have this chestnut extract, which is easier for use with yarns.
 
Horse chestnut is known in natural medicine as an anti inflammatory, but we are looking at the bark a great dyer. Rich in catechic tannins, about 30-40%, it is used in the tanning industry to tan leather.
 
Use on all fabrics  50-100% wof, always soak barks before heating to fully release the tannins. Heating is needed. Boiling will dull the hues.
No mordant is needed, but alum will give more yellow, copper will yield soft orange hues.
 
This is a sustainable and renewable source of dye from Europe. Organic.