As part of some outreach work, one of us (David), visited the conservation department of the
Oak Galls to Ink
Westminster Archives, to assist with making some Iron Gall ink for use in the archives and to take some back to the Apocalypto Project lab for experimentation.
The history of iron gall ink manufacture includes plenty of alchemy, many recipes for ink include (some or all of)Â urine, vinegar, blood, resin, wine and spirits. In the modern era we know that the active ingredients and a source of tannins and a source of iron ions.
We decided to standardize upon the following recipe.
Boil 2g of powdered oak galls in 200ml of water for one hour. While solution is still hot, add 24g of Iron (II) Sulphate. When all the Iron Sulphate is dissolved, add in 4g Gum Arabic. Filter the solution and bottle.
Boiling oak galls for ink
Upon adding the Iron (II) Sulphate to the oak gall infusion, a dramatic colour change occurs; the pale orange/brown liquid turns deep blue-black, indicating that the tannins from the oak galls have formed chemical complexes with the iron ions. When all of the iron (II) sulphate dissolves the ink needs filtering to remove insoluble particles.
The whole process took just over three hours, the majority of that time spent filtering the ink, finely powdered oak galls clog filter-papers wonderfully.
Meagen Smith has also written up the ink making adventure.