About Oak Galls (Gall nuts)
Oak galls (sometimes called oak apples or gall nuts) are small to medium-sized round hard growths that are high in tannin, and are an ancient mordant. They are an essential ingredient in making oak gall ink and can also be combined with iron to produce gray to black shades on textile fibers.
The gall is formed when an oak leaf bud or large leaf vein from the Qurecus infectoria oak is invaded by the gall wasp. The wasp larva exudes a chemical that creates a protective housing (the gall) so it can feed and undergo metamorphosis into adulthood. The adult wasp exits the gall leaving behind a tannin-rich ball.
Our oak galls are often referred to as Aleppo Oak galls as they come from the Aleppo oak tree (Quercus infectoria). The tree is native to Southern Europe, Turkey, Syria, Iran, Iraq, Cyprus, Lebanon and Israel.
By itself, oak galls make a light beige color. When dipped in an iron afterbath, the color quickly changes to a gray or “black” shade.
We offer whole oak galls, powdered oak galls, and gallo-tannin extract (extract of oak galls). The whole oak galls need to be crushed into powder before use. The powdered oak galls have been crushed and sifted, and the extract is a more concentrated preparation of the oak galls.
Use oak galls at 10-15% weight of fiber. Crush whole oak galls before use. Available in 100 gram bags.
Gallo-tannin extract (oak gall concentrate)