What is Dry-Hopped Beer?
Dry hopping is a brewing technique that originated centuries ago in Britain – it referred to the addition of whole hop cones, known for their antibacterial qualities, to the cask of matured beer in part to preserve it while being transported without refrigeration. Later, with the explosion of US craft breweries in the 1980s, dry hopping was adopted by a new wave of brewers who sought to maximise the hop character of their beer. Now UK craft brewers are in on the act, dry hopping almost all kinds of beer, from Pilsner and IPAs to sours and stouts. So how does it actually work and what results are they trying to achieve? We spoke to some of London’s most able exponents of dry hopping to find out more.
Adding hops in brewing process
In the process of making beer, the hops are usually added to the boil in three stages – at the beginning of the boil, several minutes before the end, and at the very end as the heat comes off. Hops added first contribute mainly bitterness to the final beer, hops added later in the boil – flavour hops – contribute some of the bitterness and some of the flavour, and lastly the hops added at the end of the boil add aroma. Hops contain alpha acids, beta acids and essential oils. During the boil, essential oils and beta acids evaporate, while alpha acids are dissolved in the solution, making the beer taste bitter. The later the hops are added, less alpha acids dissolve and more beta acids and volatile essential oils stays in the finished beer.
When we talk about dry hopping, we mean that dried hops (or hop pellets) are added to either the fermentation vessel or conditioning tank post-boil. Brewers will often suspend mesh bags packed with hops in the beer like a giant teabag. Other approaches involve circulating the beer through a column of hops, as in Sierra Nevada’s eponymous Torpedo IPA. However it’s done, the aim of dry hopping is to extract and retain as much of the essential oils in the finished beer as possible.
Compared with the fruity flavours associated with late hops, dry hops give more grassy, herbal and resiny aromas. Graham from Hackney’s acclaimed Pressure Drop Brewing explains that the aim of dry hopping is to “elevate the aromatic profile of the beer, recreating the experience of sticking your head in a bag of fresh hops”. Their Pale Fire and Bosko IPA both undergo dry-hopping while Bosko Absoluto, their Imperial IPA, is double dry hopped. Around the corner at East London pioneers Five Points Brewing Company, all batches of Pale, IPA & Hook Island Red are dry hopped. In the words of brewer James Allen, “dry hopping is all about adding a load of hop aroma to the beer without adding any bitterness; since most of what we taste actually comes from aroma, dry hopping can really elevate a beer’s flavour and make it pop”.
While a wide variety of hops are used for dry hopping, those with lower alpha acids – e.g. Cascade, Galaxy & Saaz – are often preferred as they contain a higher proportion of essential oils. Up in Tottenham Hale, Beavertown Brewery make some of the most memorable and sought after dry hopped beers in the UK. Their Gamma Ray APA epitomises the lure of dry hopped beers with a refreshing, herbal character overlaying more fruity, late hop aromas of grapefruit and mango. Beavertown brewer Tiago Falcone told us that Gamma Ray is dry hopped with big US varieties such as Amarillo and Citra. Both these varieties contain very high levels of highly pungent Myrcene oil, also found in herbs such as thyme and lemongrass, and characterised by woody, green, vinous & peppery aromas.
We hope that the next time you pour yourself a glass of dry hopped American Pale Ale or a big, explosive Double IPA, you enjoy the refreshing, herbal quality imparted by hops added to the beer post-boil. Below are a few of our favourites to try.