The cross-breeding of different hops has been driven by craft brewing

The cross-breeding of different hops has been driven by craft brewing

Up until around 15 years ago, the range of hops used by the brewing world was, at best, limited. The explosion of craft brewers of late, however, has led to a renaissance. Simon Jackson, executive director of the Institute of Brewing & Distilling, considers the role of hop breeding in beer innovation.

The contribution of hops to beer through their ability to impart bitterness and aroma is well known. During the 1970s, through to the late-1990s, it was all about the bittering potential through the alpha acid content of hops for the brewer, the grower and the breeders.

Varieties such as Columbus, Admiral and Herkules were developed as so-called ‘super-alpha’ varieties. Although alpha is still of pre-eminent importance when scale purchasing decisions are made - and remains the mainstay for many hop growers - the global craft beer movement has really shaken up the scene in the last ten to 15 years. 

Highly aromatic hops coming out of the north-west of the US (many with distinctive English or European varietal parentage) have caught the imagination of the craft brewers, initially in the US and now in the UK and the Australian and New Zealand craft scenes. This trend is now being followed by the larger regional breweries in the UK through ‘single hop’ seasonal ales. We also see global brands referring to the aromatic hops that are being used – Saaz from Czech and the spicy Strisselspalt from Alsace.

Hop gardens are once again busy and the labours of specialist breeders are working hard to breed new varieties that take aroma and flavour to new highs. The move has highlighted the need to protect the range of the hop germplasm that is maintained in collections to allow the creative recombination of interesting aromas. Obviously, there has to be a balance between drinkability and flavour impact, but aroma is certainly playing a full part again. This reawakening of interest in the contribution and diversity of hop flavours can only be good for the global hop industry. 

These re-energised breeding programmes are a global phenomenon. In the UK, a well-structured hop breeding programme at Wye College - supported by government funding - was considered low priority just at the low point of interest in hop varieties; a sorry position, given the importance of Fuggle and Golding as parental stock at a global level.

But, the hop farmers could sense that the worm was turning and set about a plan to keep the breeding programme alive. Funding from farmers, brewers, trade associations and the Institute of Brewing and Distilling (IBD) was secured and the Wye College collection was saved and moved to a new home under the auspices of Wye Hops Ltd.

The UK National Hop Association now has a breeding programme run on its behalf by Wye Hops. Most recently off the blocks is a new variety, Endeavour, which has just reached the farm trials stage. With a distinct citrus note, it provides a unique flavour for an English-grown variety and has been likened to some of the imported flavour hops from the US. Endeavour is only available in limited quantities whilst it is being established on a few farms. Like many of the flavour hops, it has an alpha-acid content well above that considered typical of a classical aroma hop.

Wye Hops is also re-assessing the germplasm collection looking at older varieties which provided flavours less acceptable a few years ago, often because they were too strong or intense. These may well be of interest for this new trend.

Dr Peter Darby, the ‘breeding supremo' for this programme, says: "Many of the crosses made over the last ten years have been aimed at flavour and aroma with, for example, crosses in 2010 based on Fuggle, and in 2011 based on Cascade and recombination of diverse genetic sources. In these years, such crosses accounted for more than 75% of our breeding effort."

UK brewers continue to support this re-energised programme and the IBD has made further grants to support this work and also to support work on disease resistance and managing the climate change of warmer springs and wetter summers. 

This new category of ‘Flavour Hops’ is, in some ways, very similar to those seen in New World wines, with their more powerful aromas and flavours. In this context, the arrival of Flavour Hops whilst driven by the craft brewers is certainly chiming with consumers – hence the outbreak of hop varietal detail on labels and marketing material. The ability to introduce exciting spicy and fruity aromas to beer is also part of the explanation for the rise in the popularity of beer and food matching. Indeed, an important part of the Beer Academy's Beer Sommelier assessment is an understanding and recognition of complex hop flavours.

There are new varieties coming through all the time. From the US, we have seen Citra, Simcoe, Summit, Centennial, Amarillo and most recently Delta, Calypso and El Dorado.

From New Zealand, we see Nelson Sauvin, Motueka, Riwaka, Pacific Jade, and this year’s new additions Wai-iti and Kohatu. From Australia, Galaxy, Stella and Summer.

This year, Dana from Slovenia has been picked up for its aroma and flavour. The Slovenians also have a very fruity range of hops coming through the breeding programme, with flavours from elderflower to orange.

Even in Germany, where traditional beer styles (and de facto alpha) are king, the citrus aromas are being researched with new trial varieties from Hüll such as Polaris and Hallertau Blanc. They tempt us with descriptions of hops containing melon, grape and passionfruit.

It seems that hop breeding around the globe has been diverted away from high alpha to high aroma. This is a key element behind the exponential NPD effort among brewers in using hops as a flavour differentiator, as well as generating a point of interest for the new generation of beer aficionados.

This renaissance of the importance of hop aroma also bodes well for traditional varieties – some of which have held their place in the hop gardens only through the emotional attachment of a few visionary growers and farmers. 

So, move over Shiraz and Sauvignon Blanc – make way for Galaxy, Fuggle, Nelson Sauvin, Citra and Endeavour.