[c] London East End brewer Charrington's trial shipments of hogsheads of "India Ale" to Madras and Calcutta in 1827 proved successful and a regular trade emerged with the key British agents and retailers: Griffiths & Co in Madras; Adam, Skinner and Co. in Bombay and Bruce, Allen & Co. in Calcutta.

[18] Early IPAs were only slightly higher in alcohol than other beers brewed then, but more of the wort was fermented, meaning few residual sugars, and they were heavily hopped.

[19][20] While IPAs were formulated to survive long voyages by sea better than other styles of the time, porter was also successfully shipped to India and California.

[24] Some brewers dropped the term "India" in the late 19th century, but records indicated that these "pale ales" retained the features of earlier IPAs.

Worthington's White Shield is an example of a historic India Pale Ale, first brewed in 1829 principally for export to the British Empire.

By the 1960s White Shield had become a cult drink brewed in small quantities for a dedicated following, but it found renewed popularity in the early 1970s when the demand for real ale grew in the UK.

[33][34] The revival of IPA in modern times dates to a seminar on Burton pale ales organised by publican Mark Dorber at his pub, the White Horse, Parson's Green, in 1990.

[35] Dorber and Roger Protz then organised an IPA conference in 1994 at Whitbread's brewery in London, attended by brewers from both sides of the Atlantic.

[36] The influence of this meeting persists, for instance Brooklyn Brewery's East India IPA is based on the beer that Garrett Oliver took there.

American IPAs are hop-forward in character, with classic examples from the West Coast of the United States in the 2000s (first decade of millennium) being especially bitter.

[42] They often have brilliant clarity and are dry with minimal malt character, although some slight haze caused by high hopping rates is common and acceptable.

A few years later, Noonan's protégé, Glenn Walter, embittered by a pending divorce, brewed an extremely bitter version of the beer, named Blackwatch IPA.

The substyle is typically made partially in the style of American macrolagers, such as Anheuser-Busch's Budweiser or Miller's High Life, with a malt bill that includes a substantial portion of maize, rice, or dextrose adjunct, and the use of lager yeast, and partially like an American IPA, with hops added to provide both substantial bitterness and hop flavors and aromas, and fermented at temperatures warmer than commonly used for lager fermentation (14-17°C).

[54] [55] With the extreme dryness and bitterness of West Coast IPAs, some beer connoisseurs have observed that IPAs in some parts of the United States, especially in the Upper Midwest and Great Lakes states, have a maltier backbone and flavor profile that is more balanced between bitterness and hop presentation and malt character.

These observers point to beers such as Bell's Brewery's Two Hearted Ale and Surly Brewing's Furious IPA as examples of this phenomenon.

[56] Characterized by juicy citrus and floral flavors, with an emphasis on hop aroma with lower bitterness, they also have a smooth consistency or mouthfeel, and a hazy appearance.

[61] It was officially recognized as a separate beer style, the Juicy or Hazy India Pale Ale, by the Brewers Association in 2018.