"The best inks are grown, not manufactured. Oak galls have been writing history for two thousand years.
"KaiRenner26th of April 2026
What Is Oak Gall Ink?
Oak galls are small, round growths that form on oak trees when a gall wasp lays eggs inside a leaf bud. The tree responds by producing a hard, tannin-rich sphere around the larva. When you crush and steep those galls, you get a liquid rich in tannic and gallic acid. Add iron sulfate and the reaction turns the liquid a deep, permanent blue-black that bonds chemically to paper fibers rather than just sitting on the surface.
What You Need
Gather 10 to 15 dried oak galls, 1 teaspoon of iron sulfate (ferrous sulfate),
What You Need
Gather 10 to 15 dried oak galls, 1 teaspoon of iron sulfate (ferrous sulfate), 1 teaspoon of gum arabic, and 250 ml of water. You can find iron sulfate at garden centers sold as lawn tonic. Gum arabic is available at art supply shops or online. Collect
Crush and Steep the Galls
Break the galls open with a hammer or mortar and pestle.
Crush and Steep the Galls
Break the galls open with a hammer or mortar and pestle. Place the crushed galls in a jar with 250 ml of water. Let them steep for at least 48 hours at room temperature, or simmer gently for 30 minutes to speed extraction. The liquid should turn dark
Add Iron Sulfate
Dissolve 1 teaspoon of iron sulfate in a small amount of warm water, then stir
Add Iron Sulfate
Dissolve 1 teaspoon of iron sulfate in a small amount of warm water, then stir it into your strained gall extract. The liquid will shift almost immediately from brown to a deep grey-blue. This is the iron reacting with the gallic acid to form iron
Add Gum Arabic and Finish
Stir in 1 teaspoon of gum arabic to give the ink body and help it flow smoothly
Add Gum Arabic and Finish
Stir in 1 teaspoon of gum arabic to give the ink body and help it flow smoothly from a nib. Without it, the ink can be too thin and feather on paper. Bottle the ink in a small glass jar with a tight lid. Let it rest for 24 hours before use. The ink will
Shelf Life and Storage Oak gall ink can grow mold over time. Add a few drops of clove essential oil or a small piece of gum benzoin to the bottle as a preservative. Store in a cool, dark place. If the ink thickens, add a few drops of distilled water. If you see white or green mold forming, discard that batch and start fresh. A well-preserved batch can last a year or more.