Extracting Yellow Dye from Weld Plant — The Oldest European Yellow

Harvest weld stalks (Reseda luteola) when the plant is at full flower — this is peak luteolin content

Chop the stalks, leaves, and flowers into 5 cm pieces to increase the surface area for extraction

Weigh the chopped plant material — you need equal weight of plant to the weight of fibre you plan to dye

Fill a dye pot with cold water and add the chopped weld, submerging all plant matter completely

Heat the dye bath slowly to 80°C — do not let it boil, as temperatures above 90°C dull the yellow

Maintain the bath at 80°C for 45 minutes to extract the luteolin pigment from the plant cells

Strain the dye bath through cloth to remove all plant matter — the liquid should be a deep gold

Return the strained dye liquid to the pot and reheat to 70°C

Dissolve alum at 10% weight-of-fibre (e.g. 20 g alum for 200 g wool) in a cup of hot water

Pour the dissolved alum into the dye bath and stir thoroughly to distribute it evenly

Wet the wool or fabric thoroughly in warm water before adding it to the dye bath

Lower the wetted fabric gently into the alum-dye bath, pressing it below the surface

Heat gently to 80°C and hold for 1 hour, turning the fabric every 10 minutes with a stick

Lift a corner of the fabric to check the colour — it should be a rich golden yellow when wet

Remove the dyed fabric from the pot when the desired depth of colour is reached

Rinse the fabric in progressively cooler water until the rinse water runs clear

Squeeze out excess water gently between your palms — never wring or twist the dyed wool

Hang the dyed fabric in shade to dry completely — direct sun on wet dye can cause uneven fading