Here’s a batch of Yoghurt and Bruesli that’s been two-and-a-half years in the making: #Yobro 9.3% Barrel-Age Soured Yoghurt & Bruesli. #Yobro obviously standing for ‘you only brew once’.
We’ll let Kelly tell you more about the two-and-a-half year long process:
Way back in the beginning of 2015, I had an idea to use a slightly unconventional strain of ale yeast to produce a slightly unconventional beer.
Whenever I had tasted beers brewed with the various incarnations of Brettanomyces bruxellensis, I’d always been impressed with the aroma profile that said yeast strain released during ferment.
When younger, the beers would sing of fruitiness with everything from stewed pineapple to dried papaya coming to the fore. And as beers with this strain aged, they tended to start showing some subtle (and classic) ‘Brett Character’, often in the form of a slight funkiness, sometimes referred to as being slightly leathery, medicinal or haybarn-like.
So based on that, the concept for Yoghurt & Bruesli was born. This beer was to bring together the various elements of a bunch of different cereals, malted and otherwise, as the ‘Brewer’s Muesli’ aspect and this was to be accompanied by the fruitiness that the B.bruxellensis would provide. Some type of odd, abstract, alcoholic breakfast beverage.
The Yoghurt part was to be provided by a couple of bacterial cultures that are utilised in both cheese and yoghurt manufacture: Lactobacillus delbrueckii and Streptococcus thermophilus. These two strains act in tandem to convert sugars to lactic acid, one of the many compounds that give tartness to some sour-flavoured beers, as well as the evident acidity present in yoghurt and some cheeses. Usually these bacteria will convert lactose (milk sugar) to said acid, however I wasn’t keen to use lactose as an additive in this beer, so relied on the breakdown of other simple sugars that had been taken from the original grains.
The beer was brewed as per usual, a mixture of Barley and Wheat malts, Flaked Rye, Flaked Spelt, Rolled Oats and Flaked Maize. The subsequent sugary wort was then cooled down and the yoghurt bacteria strains were added under a layer of carbon dioxide. These bacteria prefer to perform in an oxygen free (anaerobic) environment, so this was to assist the souring process. After just under two days, the wort pH had dropped enough for my liking and the wort was boiled, a small amount of three-year old hops were added and the beer was fermented with a couple of strains of Brettanomyces bruxellensis.
After a month or so, a portion of the beer was transferred to a French Oak barrel that had previously held some Marlborough Pinot Noir. The oak itself had been well used, so the hope was that not a lot of oak character would transfer to the beer, however as a consequence of a long resting period in the wood, there is definitely some character!
After entering the barrel, the 2015 Yoghurt & Bruesli was then pitched with some more active Brettanomyces as well as a couple of yeast and bacteria blends from an American yeast supplier. The Lambic and Roeselare blends provided some new Brettanomyces strains as well as a combination of Lactobacillus and Pediococcus in the hope of further secondary fermentation within the barrel.
The #yobro was then tasted throughout its two-and-a-half year slumber in oak and finally transferred to stainless, carbonated and prepared to be put on tap.
The hungry beasties chewed through some of the more complex sugars remaining in the brew and it has hit 9.3%
Be sure to come and have a taste. Initially we have just put on 10 litres of this rare and complex beast, but more will follow! Expect layers of aromatics, oak character, boozy, yet smooth flavours and a slightly tannic bitterness.
Why #yobro? Well… at this stage it’s a beer that You Only Brew Once! Who knows, though? It may come and visit again…