How to Make Oak Gall Ink (Iron Gall Ink Recipe)

Oak gall ink, also called iron gall ink, has been the standard writing ink in Europe and the Middle East for more than a thousand years. It is made from tannin-rich oak galls, iron sulphate and gum arabic. This recipe was shared with us by Maydi Díaz of Sunday Scriptorium.

Ingredients

• 1 oz (28 g) green oak galls
• 12 fl oz (350 ml) rainwater or distilled water
• 1/4 oz (7 g) iron (ferrous sulphate), powdered
• 1/2 oz (14 g) gum arabic powder
• 1/2 fl oz (15 ml) white vinegar
• A small piece of natural linen and some twine
• A 12 oz (350 ml) or larger glass jar with a lid
• Cheesecloth for straining

Avoid metal tools and containers where possible: the ink is acidic and corrodes metal quickly.

Method

1. Crush the oak galls into small pieces with a mortar and pestle.
2. Wrap the crushed galls in the linen and tie the bundle with twine.
3. Place the bundle in the jar with the water, seal it and leave it for 6–7 days.
4. Pour the liquid and the bundle into a pot and simmer until 12 fl oz reduces to about 8 fl oz (240 ml).
5. Strain through cheesecloth.
6. Stir in the iron sulphate, gum arabic and vinegar, then let the ink cool.
7. Strain once more before bottling or using your ink.

The ink looks pale when you first write with it and darkens to a deep black as it oxidizes on the paper.

Tips

• Green oak galls contain the most tannin and give the darkest ink.
• Use more gum arabic for a thicker ink that sits on the surface, less for a thinner ink.
• Store the ink in a sealed glass bottle away from light.

Prefer to buy ready-made ink? You can find Maydi's oak gall ink in her Etsy shop.

Related: Complete oak gall tannin guide · Gum arabic and dye assists