Oak apples and other galls have been used to make ink since at least Roman times, and it was the most commonly used ink from the 9th to the 20th century in Europe – it is still used for legal records in the UK such as birth, marriage and death certificates because it is both permanent and waterproof. Best used in a disposable quill pen rather than your best fountain pen!
To make it, first you need some galls that have been vacated by the wasp and are dry. Crush them to powder, then add warm water and iron in some form, eg rusty nails or filings, and cover. Keep in a warm place to ferment for a few days. Then drain off the ink, filtering out the solids if necessary, and store it in an airtight container. It has a fairly short shelf-life; oxidation reveals the ink and turns it darker on the page, but isn’t so helpful before it has been formed into writing! The ink is also quite acidic, being formed from tannic acid and iron – although apparently crushed egg shells can be used to neutralise it and prevent it from degrading the paper.Medicinally oak apples can be used like oak bark to stop internal bleeding. However while chewing bark is fine, I cannot recommend chewing an oak apple – they are about the most astringent of all vegetable compounds. Instead, use a decoction. They are also known for curing dysentery.
There is not a lot of folklore associated with the oak apple. However, it is said that if a “worm” (larva) is found inside the gall on Michaelmas Day (29th September) then the year will be pleasant and unexceptional, if a fly is found inside it will be a moderate season, but if a spider is found, then it will be a bad year with food shortages and ruined crops. If nothing is found however, then serious diseases will occur all that year.The oak apples used to have a much greater significance in England, being used as decorations on Oak Apple Day, 29th May. The mid 1600s saw civil war in England, followed by a very Puritan Commonwealth rule. All sorts of traditional festivities and activities were banned, such as Maypole dancing, Christmas decorations or feasting, carol singing, theatres, inns, football or other sports, walking on a Sunday except to or from church, and even wearing colourful clothes or makeup etc. Even the various Medieval Saints’ Feast days were stopped, and instead Fast days were introduced once a month. It was on his birthday, 29th May, in 1660 that Charles II rode triumphantly into London to return as King. The day was declared a holiday and was entirely given over to dancing, feasting and merry-making – and the event was repeated every year. The story of how he hid in an oak tree to escape parliamentarian forces became widespread and led to the Oak tree becoming the symbol both for this day and of England. To show their loyalty and support for the monarchy and its restoration, doorways were decorated with oak boughs and people wore sprigs of oak in their clothing or on their hats – of which oak apples are the most decorative part at the end of May. They were liable to be punished with pinching or nettles if they failed to do so! While this holiday has become much less known since the Victorians removed it from the official calendar (a day given over to merry-making didn’t fit well in that period!) it is still celebrated in various villages and towns around the country – including Castleton in Derbyshire where they hold a garland parade every year on this day.