This coincides in its main thrust with that given in the recent major work on IPA, Pete Brown's Hops and Glory. In the detail, neither author seems to have been aware of the other's work (there is an amusing difference of interpretation of the "teapot legend", for example).
One problem of Mr Pryor's paper is that the crucial statements which are made about what the beer itself was actually like are not documented. Mr Pryor repeats the old story common to a hundred homebrew books and a thousand web pages, comprising the following theses:
* IPA was a new product designed for India
* it was made pale and hoppy to survive the sea journey
I won't go into these here. Happily, the tale that it was extra strong for added protection against spoilage does not get repeated. Ron has argued convincingly that 19th-century IPA, though strong by comparison with present-day English bitter, was one of the weaker beers of its day, and only the peculiarities of the taxes in force at the time stopped it from being even weaker.
Interestingly, Pryor adds one thesis of his own which I have never seen before:
Hodgson's innovation was to put additional dry hops in the barrel of finished beer to improve the beer's chances of surviving the long voyage to India. This was intended to stabilise the beer against the constant rocking motion in the ship's hold.As evidence for this, we are offered a citation from a contemporary source about a shipwreck in 1835, after which the unfortunate castaways sustained themselves by chewing the hops and dregs from a barrel of Hodgson's ale. The problem is that this proves only that Hodgson was dry-hopping in 1835. It does not prove that he was doing it in 1787, and it does not prove that the practice was his innovation.
Whatever its origins, dry hopping was being practised widely by the 1820s. William Cobbett's Cottage Economy (1823) tells the would-be brewer to "Put in a handful of fresh hops" when filling beer into casks for storage. Mary Eaton in The cook and housekeeper's complete and universal dictionary (1822) gives the same advice: "When the working [fermentation] has ceased the cask is again filled up with the surplus beer and a handful of fresh hops being added the bung is finally closed down".
And neither of these works treat the practice as a novelty. There's no mention that the practice was relatively new, or that it was associated with beer exported to India, nor is there an explanation of what could go wrong if you failed to do it.
On the other hand, if we look at brewing texts for the period before the trade to India took off, the picture is a bit different. Watkins in The compleat brewer (1760) doesn't mention dry hopping in his discussion of October beer (the pale beer brewed for keeping, thought to be at its best two years after brewing — Pete Brown reckons this to be the contemporary beer most similar to what Hodgson would have sent to India). Neither does Combrune's Essay on Brewing (1758).
The smoking gun I'm looking for is pretty specific: a reference to dry hopping before the 1780s. Otherwise we are faced with the questions of who actually did start doing it, when and why. Maybe it was even Hodgson?