If you’ve been following our story lately, you may know that Gove, Eddie and I, the founders of Black Hops, recently completed a “not-so-secret” mission overnight to brew a wild fermented beer.
With the upcoming launch of the AWOL barrel-aged beer brand and restaurant, we wanted to use an old brewing technique called spontaneous fermentation to create a unique one-off barrel-aged beer that we could taste at the new AWOL restaurant in about nine months’ time.
Fermentation is a stage in the brewing process in which yeast converts the carbohydrates in the wort into alcohol and carbon dioxide, thus giving the finished beer its alcohol content and carbonation.
This fermentation begins during the prescribed brewing process when the cooled wort is transferred to a cooling vessel and a specific yeast strain chosen by the brewer is added.
Yeast has been found floating in the fermented air, looking for something to ferment in any environment you can find – from suburban parks and gardens to forests, creeks and orchards.
There are many different kinds of yeast, and only some of them are good at fermenting beer. Modern brewing primarily involves the controlled use of known yeast strains in the fermentation process.
Today’s standard brewing yeast originated from cultivated wild yeast, which over time was considered an excellent yeast for fermenting alcohol in maltose mixtures and producing satisfying flavors and aromas. But this was not always the fermented case.
The concept of spontaneous fermentation can be traced back to how beer was made before yeast was cultivated in a laboratory setting for commercial and health purposes.
Before the days of Louis Pasteur, the godfather of fermentation and pasteurization, brewers didn’t even know that yeast and fermentation existed, and the action of alcohol was revered as sacred magic.
In the early days of brewing, brewers fermented would inoculate their beer with wild yeast colonies that floated in the air at the time of inoculation.
All beers are “open fermented” and undergo this natural fermentation process. Some breweries, notably the Belgian Lambic-style breweries, are known for the presence of wild yeast strains in their brewing environment.
To date, all of our dark hoppy beers have been brewed by adding known yeast strains, including our sour beers and those aged in barrels at AWOL. This means there is a lot of spontaneity and unknowns in brewing our first wild yeast ale.
In fact, we’ve accepted that our first fermented attempt at brewing beer this way will probably not work, but we think it’s a fun and educational thing to do anyway.
It’s also a starting point for trying more methods in the future, and we think it’s worth the time and effort to capture some yeast that we can use in future AWOL beers with a cool story attached.
Wild yeast can produce a range of flavor effects – some great, some not so tasty, and some just plain weird. So while there’s an element of risk, the rewards of nailing an epic wild yeast beer become irresistible.
The plan was simple – head to the Gold Coast hinterland to a property on the banks of a spur entrance to the Talle Valley’s Tallebudgera Creek and build the original dark hop brewing kit, letting whatever wild yeast and bacteria are in fermented the air do the work.
Being away from the city means the air is less likely to be contaminated with airborne pollutants that can disrupt the natural fermentation process. So while there is still some luck as to exactly what type of wild yeast is in the beer, it’s more likely that you won’t have to pour it out at the end fermented of the brewing process.
Once we had the tester ready at the creek, we got into the nitty gritty of the brewing process, cooling the wort and transferring it to fermented an open container in the creek (behind a bug net to keep out insects and frogs).
This was a bit like our version of Coolship brewing – coolships are wide, open, flat brewing vessels that act as a giant pool for any wild yeast and bacteria floating in the air at the time to innocolate and ferment the beer.