Galls can be treated in different ways to make iron gall ink.

The following procedures can be used to extract the tannin (gallotannic acid) from the galls and also to increase the amount of gallic acid.

At first, make a mixture of crushed or ground galls with vitriol, and gum Arabic in liquid and then the solution are filtered if needed. In this method a minimum of pure gallic acid can be produced but, since the iron also reacts with gallotannic acid directly, a strongly colored ink can be produced. The ingredients can also be mixed dry, which will produce ink the moment water was added to it. This powder makes for a perfect traveling ink, creats only as needed to avoid the opportunity for mold growth. A transportable ink can also be prepared by drying the made iron gall ink, and resolubalizing for later use by adding water.

Boiling crushed or ground galls in water (wine, beer, etc.) can be extracted most of the gallotannic acid and gallic acid from the galls. Addition of an acid (vinegar, hydrochloric acid) also serves to increase the percentage of the gallic acid.

Fermenting the crushed galls by soaking them in water in a warm place can be produced the highest yield of pure gallic acid. The mold reacted with the glucose in gallotannic acid and hydrolyzed it to form gallic acid. Various sources mention that fermentation for ten days will be long enough to allow a complete transition of gallotannic acid to gallic acid.

After the tannic acid are obtained, it can be mixed with vitriol and gum Arabic. Other ingredients can also be used to modify the characteristics of the ink:

• Natural and synthetic dyes increased visibility of a freshly prepared ink (logwood, indigo, aniline dyes).
• Pomegranate rind, walnut husks, and various tree barks could be added for extra tannin.
• Vinegar or other acids mitigated the premature precipitation of the ink complex.
• Sugar, honey or gum created a more brilliant and slow-drying ink.
• Carbolic acid, alcohol, vinegar, cloves, different salts or alum slowed mold growth.
• Brandy protected against freezing.
• Rain water, beer or wine used in place of standing or pumped water sources produced fewer impurities.