1# dry wool
4 oz. aluminum sulphate
1 oz. cream of tarter
Dissolve alum and cream of tarter in 4 – 4 1/2 gal. of cold, soft water. Add wool. Bring to boil slowly outdoors only. Low boil for 1 hour. Replace water as needed. Remove from heat. Allow to cool overnight.
Tomorrow I dye this wool in haskap. This is the first time I am using alum as a mordant. I can compare this later branch to the unmordanted wool scraps I dyed a couple of months ago. I am preparing a weighed quarter pound of common wool, so used 1 oz. alum, and .25 oz. cream of tarter.
[*Aluminum Sulphate produces sulphuric acid when boiling. Do not breathe. Do not use indoors.]