If you really want to know why IPA was supposedly so strong and hoppy, look not to the breweries, but to India...
Today is apparently International Let's Argue About The Mythology Of IPA Day.
One of the main points of contention about this much-mythologised style is whether or not it really was strong and hoppy, and if it was, why it was.
Wherever I've seen this point argued, it's been exclusively to do with the nature of the beer itself: did it have to be strong and/or hoppy to survive the journey? What do the brewing records say?
Some eminent brewing historians have found evidence of low strength, relatively low-hopped IPAs making the journey, which is fascinating. But some commentators have then taken this as evidence that disproves the 'myth' that IPA was strong and hoppy.
But the logic of that is flawed: evidence of weaker, less hoppy proves that IPA did not have to be strong and hoppy. It does not disprove that strong, hoppy beers went to India.
In my research for my book Hops & Glory, I found requisition orders from the India Office from the 1870s which specified the gravity, hopping rate, size of barrel, even the width of the bung on the barrel, for both India Pale Ale and Porter. When we translated the specs into modern brewing, we had a beer that was around 8% ABV and had an insane amount of hops. When we recreated it with Everards Brewery, the volume of hops clogged up the kettle and the beer was green when it came out. It was so hoppy we had to new the same beer again without any hops, and blend to two to get a beer that was still damn hoppy. But what's important to remember is that the alpha acid content - the potency of hops - is far higher now, far more concentrated, than it was then. You'd have had to had far greater physical quantities of hops in 1870 to get the bitterness from hops you get today.
Anyway, these requisitions prove that at least some IPA that went to India was very hoppy and very strong. But its presence against other less hoppy, weaker beers, proves that it did not have to be like this in order to survive the journey.
What does this tell us? Well, there's only so much that looking at the production end of things can tell us. For further clues, we have to look at the consumption side. What did people in India want their beer to be like? Throughout the whole of brewing history, this is a question that is asked all too seldom.
Another contentious 'myth' is that IPA was brewed for the troops. For some reason, there's a school of thought that it wasn't. Certainly, it wasn't the only think they drank. And yes, the civilians in India drank it too. But the big orders I saw for requisition were specifically for the he numbers of troops that were sent to India after the 1857 first war of Indian Independence (referred to by colonialists as the Indian Mutiny.)
Being a soldier in India was a life of short periods of extreme violence separated by long stretches of total boredom. The soldiers filled that boredom by drinking.
When Fanny Parkes went India on a ship full of soldiers in 1827, she came to know many of her fellow passengers and was shocked at how quickly many of them died. The average life expectancy of a soldier serving in Calcutta was just three months. Disease was a far bigger killer than combat, and much of it was caused by alcohol.
Beer couldn't be brewed well in India, but a drink known as arak could be made simply by drawing off palm sap and letting it ferment in the hot sun. Arak drinking contests claimed the first European casualties in India when the Dutch and English spice traders got there. One binge could be fatal.
So, in order to keep soldiers alive, they had to be given alcohol that was strong and flavourful, like arak, but not fatal. IPA was strong because if it wasn't, the boozy soldiers would have drunk arak instead.
As for hoppiness? The vivid hop characters we love today would have vanished from the beer after months on a hot ship. But the flavours changed. The locals used to say IPA 'ripened', and when it was ripe, they described it character as being like champagne. My sea-matured IPA certainly had that character to it - somewhere between what we think of as IPA and barley wine.
So - at least some IPA was strong and hoppy. It didn't have to be. It was like that because that's how people wanted it to be, so they drank it instead of the local gut rot.