Changes

<blockquote>In fall of 2015, we had a hypothesis concerning Penicillium roqueforti and whether it would influence a beer with a distinctive Blue Cheese funkiness. Initially, we thought it may go through fermentation because it is part of the monophyletic group, ascomycetes (which includes saccharomyces cerevisiae). However, after further investigation we realized most likely any changes to the beer would be primarily enzymatic, followed by molecular conversions which may influence the sensory characteristics.

Regardless, after outlining our goal, we reviewed Blue Cheese production for approximately two months. After speaking to some cheese manufacturers, we realized that the P. Roqueforti is typically added during the curd forming stage. The organism is encapsulated inside the cheese form but won’t develop the distinctive veins unless a microaerophilic environment is achieved. Thus, in Blue Cheese production, the wheels are “needled”.

Needling is when the cheese maker takes a stainless steel rod and pokes small holes inside the wheel, allowing micro-oxygenation, and creating a microaerophilic environment. Over time, the veins begin to grow and the distinctive Blue Cheese characteristics develop.

Our next step was to attempt the same microaerophilic environment as the needled cheese wheel, only using the properties of oak casks. We hypothesized French oak would suffice, considering it’s the tightest grain of oak used in coopering. We thought the tight grain would mitigate/minimize oxidation but allow enough micro-oxygenation that P. Roqueforti would develop.

In 2016, we inoculated a standard base beer in casks with P. Roqueforti. The base beer was mashed at a higher temperature with large quantities of oats and wheat. Our goal was to create a growth medium with the environmental conditions that promote P. Roqueforti development and subsequently residence inside the cask. This base beer was later discarded, as its sole purpose was to nourish the organism and allow the harborage of the population inside the selected casks.

The 2016 Grand Blu, was brewed during our spontaneous fermentation season (Late fall through early spring) when the outside temperature was below 47°F. Although it was inoculated with our Relic strain of yeast, we open fermented the batch for 24 hours. During the open fermentation, any resident micro flora, including acidification bacteria, joined the fermentation festivities. At approximately 5.1°P (1.020 S.G.), we moved the Grand Blu to the P. Roqueforti casks and waited.

The P. Roqueforti development took approximately 2-6 months and it added a distinctive blue/green color to the pellicle. The mycelium grew in various directions, including into the sub surface, and ultimately took over any exposed pellicle resulting from wild yeast and/or bacteria.

After the P. Roqueforti imparted its funkiness (which is subtle but both present aromatically and in the flavor profile), we moved it into steel and added the peaches. The re-fermentation increases the CO2 concentration and inhibits the P. Roqueforti from continuing to develop (at least that’s what we have experienced). When appropriate, we bottle and mature.

Since then, we have relied on using a solera method from those original casks inoculated with P. Roqueforti and blending, before going into steel to ferment with the peaches.

Grand Blu 2019 vintage has not been released, but we are hopeful it will finish maturation sometime in May.