The Experiment and the Vision
It all starts with an experiment and a vision. During the 2021 harvest, Robert and Ryan decided to conduct an experiment: what happens when the grapes brought in are allowed to begin a spontaneous fermentation? While that was the common practice for centuries, the 20th century saw huge advances in technology along with academia running more experiments furthering the understanding of grapes and the actual biochemical changes that occur during fermentation.
There was a revolution taking place that really picked up steam after the second world war. Modern sanitation practices were implemented along with the use of stainless-steel tanks which allowed for more controlled fermentation and the ability to buy commercial yeast became the standard in the industry. For those centuries before modern technology unbeknownst to the winemakers, wineries would rely on the yeast living in the vineyard to take over the fermentation. With access to commercial yeasts isolated from different grape growing regions across the world, winemakers could now dictate fermentation with a specific yeast to enhance specific characteristics that the winemaker desired in his or her product.
Rediscovering Terroir
While the technologies that were created during the 20th century have improved the wine industry for the better, there is now a lack of identity for many wines across the globe. Wines have never been more laser focused and dialed in, yet for many wines there is something lacking. The term terrior is often thrown around in the wine industry. Terrior in essence is the site in which the grapes are grown. Each vineyard site has its own unique identity, soil, topography, sun exposure, etc. To the naked eye there is an unseen world within that terrior of microbial populations that live amongst the vines and within the soil including bacteria, yeasts, molds, and fungi. Each vineyard has its own microbial ecosystem and when allowed to express itself it can transform the wine and give the wine a sense of place and identity.
From Experiment to Full Scale
Going back to where our journey began at Brengman Brothers, our experiment was very small, a stainless steel 60-gallon beer fermenting tank that was collecting dust in storage. Our process was altered compared to our normal practices. We did not settle the juice after crushing and pressing, rather we sent everything into the 60-gallon tank and we did not use any sulfur which is normally used to kill off any unwanted microbes from the vineyard. Fast forward to a couple weeks down the road, Ryan had forgotten about the experiment and was expecting the worst. What he discovered in that 60-gallon tank was something words could not describe, and he stopped everything to go grab Robert and have him taste what he had just experienced. Within days we were consulting with one of our wine club members Sadie Ingle, who holds a PH. D in Biochemistry from Stanford, about how to culture this yeast population. With her help the yeast was isolated and stored for future vintages down the road.
In 2022 the experiment ramped up to basically introduce this new process of wild fermentation to all the white wines in the program along with one red. With that came a lot of data collecting and detailed tasting notes about how the yeast was interacting with each varietal. After the successes gathered in the 2022 vintage which included a Best in Show for our 2022 Riesling Trocken from the American Fine Wine Competition, the 2023 vintage saw Robert and Ryan take this wild fermentation process full scale.100% of Brengman Brothers wines are now fermented with our ‘in house’ yeast and the results are undeniable. When comparing the sensory impacts to those of previous vintages that saw the use of commercial yeast there is a definite difference not only in aromas and flavor but also the mouthfeel.
The Future of Brengman Brothers Wines
As winemakers the thing that we desire the most is to get the maximum potential out of every single wine that is produced. We want to give the wine a distinct platform to showcase the given growing year with minimal intervention. With Northern Michigan being one of the only truly cool climates left in the world, no growing year is the same and by allowing the terrior and ‘in house’ yeast to take over the fermentation it comes full circle. While there will be similar profiles between vintages, each year there is a chance for nuisances and slight differences which is what drives the passion for both Robert and Ryan. Together they are trying to show to the entire world what is capable in Northern Michigan when wines are given an identity and a place rather than controlling certain aspects of fermentation that are often the results of using commercial yeast strains.
While the adventure is just beginning for Brengman and the winemaking team, we are now in the process of having our sample tested and identified so there can be a better understanding on the biochemical level of what our land is producing and how those microbes influence the fermentation and how the wines evolve. But what we know, the results are proof in the sommeliers swish. Our wine program at Brengman’s is focused on crafting our signature flavor profile that includes another important ingredient from the vineyard – it’s yeast! We are believers in locally derived flavors, including the yeast!