West Coast IPA

It depends on who you ask.

The BJCP counts the West Coast IPA as part of the American IPA (21A). According to the BJCP, dry, sharply bitter, clear American IPAs are sometimes called West Coast IPA, 'which is really just a type of American IPA'.

In 2023 the Brewers Association made it a separate style. The reason: many early American IPAs were brewed on the British model, with a distinct malt character. Later some brewers went for more hops and less malt, and according to the BA the category has thus 'diverged into two distinctly different styles'. Some brewers still make the older version.

You can see the difference in the Brewers Association guidelines. The West Coast style is straw yellow to gold (2–6 SRM), has little malt and no caramel or roasted malt, and is highly attenuated. The American-Style IPA may be pale to copper-coloured (4–12 SRM), with medium-low to medium malt. In alcohol (6.3–7.5%) they are the same.

For the American IPA the BJCP gives a bitterness of medium-high to very high, 40–70 IBU. The Brewers Association gives 50–75 IBU for the West Coast style. With an IPA like that you taste clear bitterness.

The hazy or New England IPA works differently. According to the BJCP it has 'less perceived bitterness than traditional IPAs': low to medium-high, and often masked by the fuller body and the soft finish. The BJCP even sees a trend towards still less bitterness in this style. The Brewers Association calls the bitterness of a juicy or hazy IPA 'soft and well-integrated' and writes that the measured IBU figure can differ strongly from what you taste.

'IPA' therefore says mainly something about a hop-focused balance, not necessarily about a lot of bitterness. According to the style guides a West Coast IPA is clearly more bitter than a hazy IPA.

IBU (International Bitterness Units) is, according to CraftBeer.com, a measure of the bitter compounds in beer, determined in the lab as milligrams of iso-alpha acids (converted bitter compounds from hops) per litre. The Brewers Association writes in its style guidelines that this figure measures one specific hop compound and does not consistently match how bitter someone perceives the beer. It gives three reasons for that: sensitivity to bitterness differs per person (partly through genetic make-up), other ingredients also contribute to bitterness, and hop aroma and flavour can strongly change the perceived bitterness.

The guidelines themselves give examples. For Export-Style Stout the BA writes that the bitterness can turn out high in the lab, but that the sweetness of the malt dampens the perception. Conversely the BJCP says of kölsch that drier versions can seem hoppier or more bitter than the IBU suggests. And in hazy IPA the bitterness is, according to the BJCP, often masked by the fuller body and the soft finish.

For orientation: CraftBeer.com gives 5–10 IBU for light lagers and 50–70 for robust, bitter IPAs. So use IBU as a rough indication, not as a flavour promise.

In master's research at Oregon State University (Barnette, 2018), dry-hopped beer was stored cool (3 °C) and warm (30 °C), with different amounts of dissolved oxygen. The storage temperature had the biggest effect on the aroma. With heat and more oxygen, tropical, citrus and hoppy aromas disappeared, and malty, dried-fruit and cardboard aromas took their place. Oxygen had a smaller, but demonstrable effect after just two weeks.

Other research, from the VLB in Berlin (2022) on eleven commercial hoppy ales, shows that it is more nuanced. Some hop aroma compounds stayed reasonably stable, other aroma compounds (esters) less so, and compounds that go with ageing increased.

The Brewers Association writes of the double IPA that the beer must show 'the fresh character of hops', without oxidised or aged flavours.

So store IPA cool and drink it fresh.