Chapelizod Heritage Association Podcast

Bonus: The Accidental Discovery of Dextrin

The Discovery of Dextrin in Chapelizod

By the early 1800s there was a starch factory in Chapelizod, possibly located on the site of the present-day industrial estate which can be viewed from the eastern boardwalk on the bridge. Potatoes were bought in enormous quantities to be used to produce starch in such factories. However, this drove up the price of the potato, which was the most important food to the people of Dublin at that time. Starch factories thus became the target of the peoples’ anger, and many were vandalised or even burned to the ground. 

Such was the fate of the Chapelizod starch factory on September 5th, 1821. Whether by accident or arson, a fire broke out and rapidly spread throughout the factory. The cries of “fire” were heard throughout the village, and people rushed to the scene, where – according to sources written some thirty years later – the factory was:

“… so freely deluged with water that the starch was washed away in streams ankle deep over the roads into the Liffey.”

Earlier that day, George IV had left from Kingstown (present-day Dún Laoghaire) to return to England. A textile block printer had spent the night in one of Chapelizod’s taverns “drinking to His Majesty’s health a little too frequently.” The following morning he woke up on the street close to the factory with a tremendous headache, only to find his clothes “stuck together by some kind of gummy substance”. When he tried to stand up, he found that his clothes had become stuck together by some kind of gummy substance. The substance was not dissimilar to the expensive glue used in his trade, gum Arabic – a natural gum produced by a tree cultivated in the lands of the Arabian Peninsula and Western Asia.

Freeing himself from his sticky situation, the man and his friends collected samples from the ruins of the starch factory in Chapelizod, and later discovered a way to reproduce this cheap gum for commercial use in the printing industry. Eventually, they sold the recipe to a man in Manchester, and despite their hopes of riches, the group found themselves poor and destitute not long afterwards, eventually emigrating to New Orleans. The formula was passed around in secrecy from Manchester to Lancashire, where eventually the recipe was revealed and manufacturers began producing it across the country, under the name of British Gum.

Dextrin is still used today in the printing of textiles, and is used as the adhesive for sealing envelopes, stamps, and the paper tubes of kitchen and toilet rolls.