Country Diary: Oak galls were a main ingredient of early inks

Oak apple galls
Oak apple galls

During recent gales, 11 grey herons had sought shelter along the bank of Johnson’s Pond, just beside Burniston Road.

Forge Valley’s bird-feeding station has been pretty quiet until recently. Despite few numbers of birds, we observed quite a variety.

We had commented on how long it was since we recorded any woodpeckers, or tree creepers, when to our surprise, from the car park we viewed three species of bird which all cling to trees. First came the nuthatch onto the bird table. Next, a tree creeper jerkily working its way up a tree trunk, propped on the stiff, pointed feathers of its tail. Finally, a great spotted woodpecker in its distinctive black and white and red plumage, briefly pecked at a decaying post to extract insects in crevices.

Masses of acorns, beech nuts and conkers have seldom been found in such profusion! Acorns have been used as human food in times of famine, though their chief use has been for animal fodder. The raw kernels are too bitter to most palates. In Europe, during the war acorns were roasted as a substitute for coffee. The kernels were chopped, roasted until light brown in colour, ground up and then roasted again.

Michael recently found three marble galls beneath an oak tree in Scalby village, close to where he used to keep his bee hives. This prompted me to search a row of oak trees locally for more galls. Amongst the leaf litter were hundreds of a strange gall I’d never before encountered – but more later.

Oak galls were one of the major plant ingredients used in early inks. They contain not only their own dark pigments, but a good deal of tannin, which fixed the ink onto the paper and stopped it fading. Until the 18th century most large households made recipes for their own individual inks. A small gall wasp had produced one of our best known plant galls, the marble gall of oak trees. It’s also known as bullet gall and oak nut. Each gall had previously contained a single larva. Marble gall wasps are not native to Britain. They were introduced from the Middle East in the 18th century, because of the galls’ high content of tannic acid used in the tanning industry, and also in the preparation of ink. Examining each gall in autumn, reveals a single hole through which a mature gall wasp has emerged.

My galls were quite different, being oak apple galls, so named on account of their rosy pink appearance when mature during May and June. By autumn they had turned brown, and were somewhat flower-shaped in appearance. We could see where fully-grown wasps had emerged through several holes in each gall.

Oak Apple Day on May 29 was named to commemorate the Restoration in 1660 of King Charles II, who hid in an oak tree after the battle of Worcester.