Last time, we went a little wild with our brew, so this year, we felt like creating something a touch more conventional, but still giving it a twist. Happily, after our initial chats with the Cloudwater team, they were of the same mind.
We settled on brewing an imperial brown ale with coffee and vanilla. This was a style Cloudwater wanted to explore more, and this was a good excuse, while for us it felt traditional enough that we knew the flavours would work, but still original enough to be interesting and worthwhile.
The only significant area of debate was around the target ABV of the beer. We’re not huge fans of high alcohol ales here at Square Mile, and felt the 9% that was initially suggested was a little high. In the end, we agreed on targeting somewhere between 6-7% ABV, meaning it’d sit between a session ale and a true imperial.
Style decided, we needed to select a coffee. It’d be nice to say we approached this in a scientific way, but truth is, the most effective method we’ve found for this process is a quick and dirty blend of brewed coffee and beer. Armed with a few cans of Cloudwater’s previous brown ale, we brewed up a batch of all our coffees and let loose!
For our part, we liked the acidity that our Colombian and African coffees brought to the beer, as we felt they added something extra, rather than just enhancing flavours already present. The team at Cloudwater, on the other hand, quite liked the extra depth our heavier coffees added. We all universally disliked the combination of natural process coffee and brown ale, however, so decided to steer well clear of that avenue.
Some back and forth later we agreed on using the Yandaro beans from Burundi. This high altitude bourbon lot brought the acidity that we liked, but also enough of the deep, traditional coffee flavours that would sit well against the roasted malts in the beer.
Additionally, after a suggestion from Tom, our Head Roaster, we decided to supply two different roasts of the coffee; one heavier, and one lighter, to ensure both elements that we wanted from the coffee came through.
For the brew, we drew heavily on the addition process we developed last year, meaning we added the coffee at two stages – the first on the hot side and the second on the cold side. The rationale here is to allow us the flexibility to monitor and tweak the strength of the coffee element as we go, but also to try and get a balanced coffee flavour through the use of different extraction temperatures.
On the hot side, we added 20kg of coffee in ten batches of 2kg to the hot wort. These additions were done by drawing a portion of the wort off into a 200L hopback, with each 2kg batch of coffee steeping for seven minutes before blending the infused wort back into the larger batch. We initially started with a ten-minute steep but dialled that back after tasting the hot wort and thinking it a little over bitter.
We also made sure we moved and worked the muslin bag that held the batches of coffee during the steep. This was to avoid any dry clumps remaining in the coffee, which is a risk when working with large amounts of grounds like this.
With the hot additions complete, fermentation with a New England yeast strain took place over a one week period and, once finished, the cold additions started.
The coffee and vanilla were both steeped with the beer together at 12°C, again in the hopback (this time sealed and purged with carbon dioxide, to avoid oxidation). Two steeps took place, and each used 12kg of coffee and took 6 hours. The vanilla was steeped for 72 hours. This made for a total addition of 10g/L of coffee in the beer, slightly less than in the Mormora Sour from last year.
Interestingly, once the final additions were complete and the beer had been given time to condition, Cloudwater got in touch to say that they weren’t quite happy with the resulting beer. It’d missed its target gravity and consequently had a lower ABV and body than expected. It was OK, but not the knockout we wanted it to be.
The solution was to brew up a second beer (which wasn’t flavoured with coffee) to blend into the first and give it more weight, sweetness and punch. This was a strong ale, specifically designed for blending that, on its own, tasted very sweet and viscous – like the sugary milk left at the end of a bowl of sugar puffs.
Cloudwater were good enough to send us a growler of each of the two beers so we could try them and test out various different blend percentages. Eventually, together we settled on a 55%/45% blend of the coffee beer to the blender beer, which gave the best balance of flavour and mouthfeel.
The final thing to sort was the label, and for this, we sent one of the Yandaro bags to the talented people at Textbook studios, where they scanned it up close to use as a background texture for the cans. We think it looks pretty great! If you’d like to pick up a can of the beer and tast it for yourself, it’s available for sale right now on Cloudwater’s website!