The dye bath of cochineal had to be maintained at 50 deg celsius, so the pan had to be pulled on and off the low ring. So a mordant of Potassium Bichromate was disappointing as I'd hoped for a plum colour and got a pinky beige. Iron gave strong grey with no real hint of pink. It was only the Alum mordant which gave true cerise pinks and was particularly successful on combed tops rather than the uncarded locks.
I then tried a second set of wools in the remaining dye bath. As well as the raw fleece I over dyed some of the iron mordanted dyed wool from the previous bath, some of the Brazilwood, and some of the Cherry bark. Straight away the iron grey came out of the wool ! Some nice pale pinks were achieved.
I should have checked this before but found out that my water is classed as "soft" which is usually great for dyeing, and particularly required for cochineal. The ph naturally is about 6 to 5.5. A bit acidic but can be modified. Interestingly though the dyestuffs have an affect on the ph too so worth a check once the dye bath has all it's ingredients together.
This is the sample done on pre carded wool. It really makes a difference to the absorption of colour.
Quite different to the uncarded ...