Humulus Olfactory Project: The Concept

Exploring new ingredients is one of the pure joys for any brewer. Exploring four new hops, in the same base beer, provides a rare chance to really gain some exposure to these new varietals. And as much as brewing the 400th batch of Out & A Bout has its own attraction; this is an exceptionally exciting opportunity.

The concept is not new. I remember Brewdog releasing similar, single-hop beers, as a mixed four-pack, over a decade ago. What a great opportunity to really explore how these flavours work. Keep everything else equal, the malt, abv and bitterness level, while just changing the hops.


The recipe development was pretty straightforward. I wanted a solid base, that could handle a significant hop volume, without tasting too burnt or bitter. I decided to keep the bitterness subtle, more like that of a Pale Ale, while the alcohol strength more like that of an IPA, the best of both worlds. The malts used were BB Pale and Golden Naked Oats. This was designed simply to carry the significant hop load. The yeast was BRY97, a neutral West Coast Ale yeast, with strong fermentation performance.

Hop selection was a lot more intriguing. I figured that to really see what is happening with hops, globally, the best approach was to choose four distinct regions. Germany, a no-brainer, where hops began, has been delighting the craft beer world over the last five years, with new products such as Hallertau Blanc, Hull Melon and Mandarina Bavaria. Showing they are more than just traditionalists. Australia, close to home, is quickly becoming recognised as a global leader in hop production, especially for tropical notes. Similarly, New Zealand has a definite terroir, and are constantly launching new varietals with exceptional character. And no discussion on hops would be complete without a nod to America, who’s thirst for strong hop flavours has created much of the industry that we love today.

So we have our four regions, the next step was to figure out what hops to select. Well, much like a chef selecting flavours in the kitchen, all brewers have a unique appreciation for certain flavours. And I wanted to seek hops with some unusual character.

Ariana, a hop I have not used before, nor had experienced in a beer, is said to have characters of blackcurrants, tropical fruits and a woody, tobacco and sometimes vanilla flavour. I did really enjoy using Sabro, which has that vanilla and woody character, so I was immediately drawn to the appeal of Ariana.

HPA-016; this is a hop we do have a bit of experience with. We have used it in pale ales, hazies and even fruited beers to good expression. It has a lovely mandarin and herbal quality that is quite unique. I choose this hop because it is a new Australian varietal and showcases where things are up to, down under.

Hort-4337, a new Kiwi hop. Although I haven’t been lucky enough to use this one yet, I have heard great things about it from fellow brewers in Australia. It’s said to be intensely peach, tropical and fruity. I thought that if we have hops that are woody (Ariana), herbal (HPA-016) and then fruity, it would be a nice differentiator.

Zappa, a neomexicanis strain from the US. I am probably the most excited about this one, although I’m trying hard not to be biased. A cross with a wild breed from Mexico, something I have never used before. It is said to have flavours of mango, passionfruit and a spicy element that makes it distinct from most of the hops grown in the US. It is also very low in alpha-acids, the bitterness compound of beer. An intriguing addition to global hop production.