Brewing Knowledge
Students spearhead research in untapped cider industry
BY LAUREN MCEWEN
For food science graduate student Manou De Pelsmaeker, hard apple cider production is a unique hands-on learning experience unlike any other she has had at Cal Poly. From spending an entire weekend milling 200 pounds of apples fresh from a local orchard to conducting critical, time-sensitive tests during fermentation, there is no shortage of firsts for De Pelsmaeker to learn from. With each day of work, she is bridging the gap of knowledge in cider production, a field of study with scant research, but a fast-growing segment of the alcoholic beverage market in the United States.
De Pelsmaeker (Food Science, ’24), along with Associate Professor Luis Castro, fourth-year food science major Tessa Murphree and fourth-year chemistry major Elizabeth Grinstead, is researching cider production techniques. She is no stranger to the research, having participated in Cal Poly’s annual BEACoN Research Scholars Symposium as an under graduate while studying the effect of yeast selection on the chemical and sensory properties of hard cider. “What makes the cider-making field very interesting to me is that the meth ods currently used in the industry don’t have a lot that’s known about them,” she said.
Her current research is focused on the methods used to process apples into pomace, allowing the pomace to rest for a period of time before pressing through a process called maceration, followed by an enzymatic treatment prior to pressing the pomace into juice, culminating in its influence on the final cider product. These methods impact the flavor and mouthfeel of the cider, especially as the maceration technique and enzymes influence the alcohol content in the fermentation process.
“Cider makers are given a variety of options for what they should do without clearly knowing which approach will yield what result,” said De Pelsmaeker. “Professor Castro and I are researching these methods so that future projects can have a clearer understanding of what results can be expected from their respective approaches.”
Castro said that the research is essential to the industry. “We hope to understand how different processing techniques will affect the cider’s chemical and sensory properties and be able to provide tools for cider makers to improve the quality of their products,” he said.
While De Pelsmaeker’s research is ongoing, some significant findings have already been revealed, such as an increased efficiency in the enzyme treatments, potentially saving cider makers nearly a day’s worth of work, she said. The research has also shown potential in increasing the antioxidant content of ciders — another possible positive marketing point for those in the industry.
No research is without its challenges. “In the fermentation process it is difficult to create and maintain the perfect conditions for these microorganisms to thrive,” said De Pelsmaeker, adding that if fermentation goes awry, it could set back research progress for weeks. The delicate balance is one that she and her team have spent countless hours, including weekends, managing.
Support from the San Luis Obispo community plays a guiding role in the cider research at Cal Poly. Jeremy Fleming of SLO Cider Co. shared the importance of collaboration on research projects and has assisted Castro and De Pelsmaeker. “I’ve offered some professional advice on how to improve the fermentations, especially with regard to enzymes and polyphe nols in traditional cider,” Fleming said. This adds a more robust flavor compared to modern ciders which offer a “cleaner style,” he added.
Fleming, who has also been a guest lecturer in Castro’s fer mentation classes, said De Pelsmaeker’s methods for applying enzymes are also a “simple solution to a big project.” Her research fills a few gaps in knowledge on cider production. “It is always nice for cider makers to know how to improve their products,” Fleming said.
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