At Su Legno we are passionate about food and beer. Over the years we have seen craft beer explode with many different styles, flavours and brands out there. Some of these we love and some shine a negative light on our industry… but that's a discussion for another day. We set out to create beer that is steeped in history and respects our industry.
Inspired by South Australian wine makers and their innovation, breweries that used exclusively wood and barrels before stainless was invented and our culinary training we set out to create a new process of beer production using conventional beer ingredients; water, malt, hops and yeast but adding an additional ingredient the charred American oak barrel. The latter is largely due to our love of bourbon. We didn’t want to produce a sour product or a barrel aged product; learn the difference between barrel fermenting and barrel ageing.We wanted to produce ales that pair well with food and can be shared at every occasion.
What we discovered is that by fermenting in barrels for a short period of time without refrigeration we were able to leverage the key conditions of yeast fermentation which impact flavour; temperature, pressure, wort composition and vessel design. This combination of variables has allowed us to create a unique barrel fermenting process which defines our beer.
How does temperature and pressure affect yeast's flavour contribution:
During alcoholic yeast fermentation yeast consumes wort sugars into alcohol and carbon dioxide. Many minor by-products are also produced and released into the beer.
Many of these contribute to beer flavour and Aroma. Major flavour compounds, the esters and higher alcohols are released into the wort as the yeast grows. The amount of these products are increased or decreased by directly controlling the temperature. Similarly to temperature pressure also impacts the formation of these flavour active compounds. The liquid within the barrel exerts a specific pressure on the yeast which is much lower than modern upright fermentation vessels. The size of the barrel also determines the pressure exerted on the yeast, that's why we use 225l Barriques exclusively.
By using a barrel and no refrigeration we allow the natural climate and pressure within the barrel determine the flavour active byproducts our house yeast produce, thus the barrel becomes a major ingredient within our recipe.
How does wort composition and charred oak define our beer:
The grains used in our recipes affect the flavour of our beer in two ways. 1. By introducing specific flavours produced during the malting process and 2. By determining the amount of simple sugars our yeast can consume to produce alcohol. During our early recipe development we discovered that dark base malts and speciality malts complemented the flavours derived from the oak itself and the barrel fermentation process. Additionally we discovered the 6% ABV was the sweet spot to support the complexity of American Oak and the barrel fermenting process without alcohol warming and therefore impacting the drinkability of our beer.
In addition to the effects of temperature, pressure and wort composition, oak and especially charred American oak imparts its own flavour compounds to our beer. Here are some examples:
furfural dried fruit, burned almond, burnt sugar
guaiacol burn overtones
oak lactone woody, dill and coconut notes
eugenol spices, cloves and smoke character
vanillan vanilla
syringaldehyde vanilla-like
These flavours can be quite intense, that's why unlike wine and barrel aged beer our beer only spends the duration primary fermentation in the barrel. This allows us to capture our yeasts flavour contribution as discussed above while subtly gaining the flavours from our charred new American Oak barrels. Similarly to pressure the size of the barrel matters for flavour, the larger the barrel used, the less oak flavours, another reason we settled on Barriques.
Conclusion:
By combining technology and materials from the past with modern brewing science and ingredients we are able to create a range of beers that are uniquely their own style and character.
