Written by Tim

A Spontaneous Blog!

Believe it or not, I generally have a schedule for blogs I want to write and things we want to cover... this blog, however, is a spontaneous piece in more ways than one! Those who follow our Instagram Story may have seen a number of 'live' videos yesterday as we collaborated with the awesome Yeastie Boys. 

It ended up as a pretty unique afternoon, and so I wanted to share with you today, a bit more about what we got up to, with a photo set from the day's events.

Before a collab, there's always a conversation between brewers in which they decide what to brew. Sometimes, it's a natural fit. For example with Finback came over from New York we just had to make one of those great IPAs they're so well known for. Or in the case of Superstition Meadery, who brought over chillis and of course, honey, a BBQ Braggot seemed to fit the bill.

In our conversations with JK from Yeastie Boys, he said he wanted to do something a little different, and so the idea of a spontaneous fermentation, barrel-aged beer was born. So.... what the hell is that, you might be asking? Well, I know I was. Whilst I did spend most of the day being incredibly excited by barrels and brewing techniques (Yes, I'm still a kid in a candy store) I also managed to ask some questions and take some photos. 

I started off climbing up to the Brew Deck to see JK and Siren Brewer, Sean, keeping watch over the freshly mashed in Wort. The recipe was designed by Siren Brewer, Kit, to be big, starchy and full of complex sugars. As we would later be using wild yeasts, the idea is that the sugars are eaten by the yeasts, which means a longer, slower fermentation and some very unique flavour profiles. 

The plan for the Wort was to be split in to two. Half would go into a Fermentation Vessel with our house strain of yeast, Vermont, and the other half would go into barrels to 'Spontaneously Ferment' outside, more on that later. With that in mind, the next step was to prepare the barrels. 

Steve, our barrel manager, had selected 6 3rd use bourbon barrels for this. That means they started life as Bourbon barrels, but have since been used to barrel age various Siren beers. Let me tell you, I wish there was some way to capture smells. After cleaning and steaming, Steve opened the barrels and that smell was incredible. Warm liquor smells that made me think of Christmas cake or sitting by a pub fire after a long winter walk, sipping a whiskey. 

Once the barrels were prepped and the beer had gone through the initial stages and into the whirlpool, I watched as Kit and Steve carefully controlled the Wort's temperature. They were looking to get it to about 75 - 80 degrees before adding it to the barrels. 

JK and Steve were happy to learn that the overnight temperature would be dropping to -2. Suffering from cold hands and feet, I wasn't. 

Temperature is key to this process. Fermentation happens at very specific temperature. When a beer goes into FV's, it can be perfectly controlled. When it goes into open topped barrels and left outside, it can't. With the outdoor temperature so cold though, the Wort would cool to the right temperature naturally. The cold also stops any unhelpful or unfriendly bacteria getting involved. 

Next step was carefully filling each barrel. These big beauties hold 180 litres, and although we weren't filling them right up, it still took quite some time. 

After JK's signed the collab wall and I took some time out to taste our upcoming Northern Monk Collab, "Rock, Paper, Scissors" with Sam and Dave (oh yes, this will be a good one) we were ready to move on...


With barrels full, and my evening workout class cancelled as I realised that this process was going to take a while and was way more fun than burpees and box jumps, the next step was to transfer the barrels to our other location. For those of you who haven't visited us in Finchampstead, we're on two sites and opposite ends of the estate. We had to move the 6 barrels the 0.3 miles, on a road full of commuters heading home and speed bumps - in the dark.

I say we, I mean Steve, with the help of Head Brewer Kyle, whilst I took photos and did little to help. The sight of him trundling around the corner, past all the cars, with 2 massive barrels on the front was genuinely funny though.

Steve's an excellent Forklift operator though, because he delivered the goods safely to their home for the night. In the dark, the three of us erected a marquee to keep them covered, took the lids off and then the fun started. 


I asked Kyle why we were spraying a Saison we brewed some years ago all over the underside of the marquee, and whilst he was looking for the scientific way to explain, I suggested "Is it to encourage the yeast?" He seemed to quite like that layman's way of looking at it, so we ran with it. 

Of course, you can't just open a bottle normally, so with Ratchet bottles sliced open with a knife and sprayed all over the underside of the marquee and my jacket, my head and my camera, we stood back and toasted a good day's work and I headed home.

Upon returning the next very frosty morning, I found Kyle and Steve (who I presume had gone home and not just camped out, but those guys are proper passionate about beer, so it wouldn't surprise me) already moving on with the next step. Apparently all the beer needed was just one night to do what it needed to do, so they were transferring it to some other barrels for the next stage.

It will now wait for about two weeks until secondary fermentation. JK is coming back with some Bacterias and Wild Yeasts he's been cultivating at home and add those. It will then be blended with the other lot from the FV and all put into barrels.... for 2 or 3 years. 

It's an odd concept, doing something like this that won't see the light of day for such a long time, but a truly exciting one. The beer industry is super exciting, with so many amazing breweries and beers available, but I get so excited by seeing experimentation like this. I for one can't wait for this one to be ready... I'll see you in 3 years!