New England IPA

According to the Brewers Association, the word 'juicy' is often used to describe the aroma and flavour of these beers. It says how the beer smells and tastes, not what is in it.

According to the BJCP, a hazy IPA gets its 'juicy' character because the brewer adds a lot of hops late in the process, above all by dry hopping, with hop varieties that smell of tropical fruit. The Brewers Association says the same: 'juicy' is about flavour and aroma that come from 'late, often very large, additions of hops'. According to the BA, a juicy character is not even required; citrus, pine, herbs or flowers are allowed too.

The yeast joins in as well. The BA mentions medium to medium-high fruity esters, aroma compounds from the yeast, that complement the hop profile.

If there is noticeable fruit in it, or lactose or vanilla, then according to the BJCP it is no longer an ordinary hazy IPA and the beer belongs in a special category, such as fruit beer. The BA counts a hazy IPA with fruit among the Experimental IPAs.

The two big style guides do not agree here. The BJCP is firm: the cloudiness arises because polyphenols from dry hopping combine with proteins from starchy grains, and explicitly not from suspended yeast ('not suspended yeast'). The Brewers Association is broader and names starch, yeast, hops, protein and other substances.

There has also been research into it. In the trade journal MBAA Technical Quarterly (2018), John Paul Maye and Robert Smith analysed twelve commercial New England IPAs. The cloudiness consisted mainly of protein and polyphenols. In six beers they counted the yeast cells: in five of them yeast accounted for less than 4% of the cloudiness, in one beer for 29%. A caveat: it is one study, from the lab of a hop supplier.

In short: yeast can contribute, but is usually not the main cause. If you see clumps of yeast or floating hop debris in your glass, then according to the BJCP that is in fact a fault.

The BJCP literally writes that a hazy IPA 'should not be sweet', although many fruity esters and a lower bitterness can give that impression. The Brewers Association also says that the fruity esters can contribute 'to the perception of sweetness'. What you experience as sweet can therefore come from the fruity aroma and the soft bitterness.

Heavy versions that remind you of a milkshake, an ice cream or a fruit smoothie fall outside the style according to the BJCP: 'IPAs should always be drinkable.' Beers with noticeably added fruit, lactose or vanilla also belong in a special category according to the BJCP.

The Brewers Association is slightly broader: lactose may be used 'to enhance body and balance', but must not define or dominate the flavour.

Sweet variants do exist, and Untappd even has a separate sub-style 'IPA - Milkshake'. But according to the style guides they are deviations from the hazy IPA, not the standard.

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.