The Gin Craze
In 1688, William of Orange, a Protestant king from the Netherlands, assumed the throne of Great Britain in the Glorious Revolution. William and the rest of the British aristocracy at the time were drinking imported genever. But the masses couldn't afford fancy imported spirits, so they started making their own cheaper version of genever, what could only be called rotgut gin.
In 1716, London was the largest city in Europe with 500,000 people and 8,000 more arriving every year. Poverty and squalor ran rampant, and the street drug of choice was cheap moonshine adulterated with industrial chemicals and sold as gin. By 1743, at the peak of the Gin Craze, the English were consuming 8 million gallons of spirits every year, almost exclusively gin. That was a gallon for every man, woman and child in the country.
Even though juniper can be grown and harvested all over Europe, it's still labor-intensive to pick and dry and distill into proper genever or gin. So, London's moonshiners got creative. They started with a low-quality grain alcohol and spiked it with oil of turpentine for that piney kick, oil of almonds to replace cardamom, and "oil of vitriol" — sulphuric acid! — for some nice heat.
Sugar from the West Indies was also cheap, so they'd cover the foul taste of the rotgut gin with lots of sweet sugar.
How bad was the 18th-century gin craze? If you read contemporary accounts, gin was worse than the crack and opioid epidemics combined. The slums of London were piled with comatose gin addicts who robbed and murdered to get their next fix. Drunken mothers were passing out and dropping their infants into the fireplace. Parents would sell children into slavery for enough money to buy another bottle.
Social commentators blamed gin for corrupting the working class, lowering the moral character of the nation's artisans, sailors and soldiers, and crippling the economy. But modern historians question the accuracy of these published tirades, often written by a British upper-class that was obsessed with the degradation of the English character. The truth was that London and other British port cities were experiencing unprecedented levels of urbanization, and the gin craze was a product of urban poverty, not the cause of it.
Parliament passed 8 different "Gin Acts" between 1729 and 1751 to try to rein in the production and sale of rotgut gin. Chemical additives were eventually outlawed and distilleries were required to register with the government.
The Continuous Still and London Dry Gin
The next big evolution in gin came in 1830 with the invention of the continuous sill. Before this innovation, all distillation was done in traditional pot stills. Pot stills are simply large copper pots in which the mash is boiled, and then the alcohol, which boils off first, is condensed and collected as a distilled spirit.
The disadvantage of a pot still is that you can only get one distillation from each pot of mash, which results in a relatively low-ABV spirit (around 50 percent ABV) that could still contain a lot of impurities and "off" flavors. And to make more booze, you have to empty and replenish the still.
A continuous still overcomes both of those problems. As the name implies, the still operates continuously, replenishing the mash as needed. The continuous process allows the still to distill purer and purer alcohol over time, resulting in clear, flavorless grain alcohol with ABVs around 96 percent.
With the continuous still, gin could now be distilled from a much cleaner and purer spirit. That meant that it didn't require as many additives to cover up the nasty flavor, although sugar was still a popular addition. The sweeter gins of the early 19th century are the origins of what's known as Old Tom gin, varieties of which are still sold today.
But at the same time, a lot of upper-class Victorians went on a health kick and decided to shun sugar. Over time, this evolved into a distinctively dry version of gin that became known as London dry gin characterized by its clean, juniper-forward flavor.
In the early 19th century, new laws in England regulated the minimum still size of gin distilleries, which put a lot of the smaller distillers out of business. This paved the way for the rise of the first big national gin brands like Gordon's, Beefeater and Tanqueray, all specializing in London dry gin.