India Pale Ale was originally a “beer”, that is, a highly-hopped malt beverage, versus the lesser-hopped “ale” which evolved from a fermented barley drink which used no hops at all.
The stocking of IPA, as it was called, was a key part of its processing. It was brewed in certain seasons, stored in casks for many months, then bottled and sold or exported. The exportation would mature it further, making the drink drier, possibly less bitter – hops wear off with time – and liable also to infection by brettanomyces, a wild yeast often resident in cask timbers or the ambient atmosphere. This aspect lent additional flavours which old books call “ethereal”, “pungent”, “apple”.
With time, this stocking became dispensed with so that while retaining its relatively dry and bitter aspect, IPA lacked certain characteristics associated with prolonged aging.
I have experimented at home with aging different IPAs for different periods, sometimes in the fridge, sometimes at room temperature. I find that only those which have a noticeable yeast sediment can stand the process – anything well-filtered generally goes off within a couple of months or so unless pasteurized (I try to avoid buying this type, though).
But yeast-sedimented IPA, whether in cans or bottle, can last a long time. The yeast slowly works on the residual malt sugars and “scavenges” as it’s called the oxygen in the container, oxygen which absent the yeast presence would spoil the beer.
Recently I tried the Toronto-based Duggan Brewery’s IPA 9, stored in the fridge about six months. While I don’t know what maturation, presumably in tank, it got before canning, I’d guess relatively little. When I bought the pack originally, the beers were very fresh-tasting and full of malt and hop flavours, a big taste indeed yet not what I’d call refined or integrated.
Six months cold storage has matured the beer remarkably. The estery elements speak out more, the American hops are less aromatic (while still present) but show a firm bitterness, and withal the beer is much better knitted than when I bought it. It struck me as a cross between Ruddles County Ale from the 80’s, Fuller ESB from the same time, and Sierra Nevada Pale Ale.
There was the faintest edge of acid, nothing the normal person would notice. 🙂 It is something which perhaps would grow if the beer was stored another 6 months. This is the last can from the pack, so I won’t have the chance to try the comparison without starting again.
I didn’t, also, keep one for the same period at room temperature. It would have been interesting to compare the two.
This kind of lengthy conditioning unquestionably benefits the beer. The old hands of IPA in British India and Victorian England knew this. While the trip to India in varying conditions of heat and humidity may have oxidized the beer – this isn’t clear since oxidation can be retarded by action of brett I understand – it probably lent the barnyard taste associated with Orval and other beers which receive a brett infusion. This is not a plus, IMO, except for those habituated. The best course seems to be to mature the beer on the lees of its yeast for months in a well-sealed container. More than less cold will never damage the beer, setting aside anything close to freezing, but warm maturation possibly can lead to even better flavours than cold aging, possibly over a different period.
I should add I decanted the beer carefully to pour it almost crystal-clear, which assisted its evolved palate, IMO. This left an ounce or so of turbid stuff which I threw down the drain.
I got the No. 9 at its sweet spot, IMO.