UNDERGROUND: Digging into coffee

Beer Teasers 300 x 300 Underground v1.jpeg

Passion Fruit Sour
Stats: 4.0% ABV. 15 IBU. 25 EBC. OG 1.039.
Hops: Magnum, Passion Fruit, Coffee.
Malt: Pilsner, Wheat.
Format: Keg, Can.
Vegan: Yes.
Tasting notes: Fruity, Tropical, Sour.



In the hunt for flavours and quality in every aspect of the brewery, we wanted to dive into the deep dark water of our morning ritual and see how far we can go. Coffee is the fuel of the brewery.

From the success of last years award winning Kingsland Coffee Stout, it has put us in the mindset to really discover what these “beans” (actually a seeds) could offer. Both the beer and coffee industries have progressed further into the science and understanding of the raw ingredients. Methods of production have advanced to present the subtle and nuanced flavours they hold. It seemed a bit crass to just throw some finely roasted coffee into a dark stout. So the journey began…

At the start of the year I called on my friend and renowned coffee expert Freda Yuan, to guide me through coffee and bring me up to speed with the how coffee has progressed. She guided me through the growing process of the trees and harvesting of the fruit, to the three types of processing. Natural processed coffee, where they leave it out in the sun to ferment and dry, Washed where they crush the fruit and wash off the fruit flesh before drying and Honeyed which is not as vigorously washed. Each containing different flavour profiles form the same seeds.

Armed with some more knowledge, we attended the London Coffee Festival around the corner at the Old Trumans Brewery! It is, as you would imagine, a huge swarm of wide eyed coffee lovers and industry professionals, buzzing with energy at all that is to offer. Equipment, roasting and brewing techniques, serving styles and most importantly tasters from the best independent roasters in the country. I highly recommend a visit if you are in anyway keen on your coffee, there is a huge depth of flavours available. One of the highlights was a coffee that tasted of blueberry muffins (I tell no lie)!

With knowledge of what coffee is and have seen what is to offer. The next phase is working out what we can do at the brewery. Darren (our head brewer) and I were fortunate enough to be able to time it with the Uppers and Downers event. An event solely dedicated to the art of using coffee in beers. From stouts to kvass, everything was on show here from the UK’s finest breweries. If anywhere would layout the possibilities of what could be done, it would be here! This was where we finally pieced together some ideas of how we could use coffee as a flavour alongside other ingredients.

In step the gang at OZONE! Independent, focussed on sustainability and local to us. We met them in their cafe down the road in Leonard Street. Their roaster is in the basement and stepping in through the door you are met with waves of fresh roasted and ground coffee aromas. We met with the team where they presented us with an array of what they can do with their coffee creations. A cold brew coffee and tonic and coffee served with passion fruit and honey infused milk were absolutely stand out.

That was it, brainwaves… Passion Fruit, Coffee, Sour.

We then had a ‘cupping’ session with all the team from the brewery (even the non-coffee drinkers). We experienced the depth and array of flavours that could be achieved and gave reasons to why they chose the variety they did (San Sebastian, Columbia), wild berries, a touch of sweetness and acidity to match the sour beer style and passion fruit’s tropical flavours.

Using the sour base from our hugely popular ‘Millions Of Peaches’, we added 100Kg of passion fruit and then we were faced with the coffee! Anson (expert barista and all round champion) from OZONE came to the brewery armed with a grinder and 100Kg of fresh roasted coffee and set to work prepping the grounds. We have just acquired what is known as a hopinator, a vessel we use for dry hopping beer. We decided to use it to essentially make a large coffee percolator. We lined the central post with multiple layers of filter paper, poured in the fresh grinds with some hot water, then pushed it into the fermenter. It took three full loads to get all the fresh brew into the beer!

Again, our genius designer, Pete Fowler has created an amazing label for the collaboration to tie the project together. As we head into autumn, we hope you enjoy it as much as we do.

Jon (and Bruce)

Beer available at Honest Brew
Coffee available at OZONE