Nov 8, 2017

The emergence of hard cider apples

From the earliest days of the American colonies, hard cider was a common staple. European settlers brought their cider-making skills with them, along with apple cultivars especially suited to the process. Yet, after prohibition ended in 1933, cider making in the United States was all but forgotten – until now.

“Since 2011 the growth of the cider industry has been astronomical,” said Gregory M. Peck, Cornell University School of Integrative Plant Science, Horticulture. “There’s been more than a 900 percent increase in the volume of cider produced in the U.S. New York has more individual producers than any other state in the country. Right now, we have about 85, and that number is growing constantly. I’m always getting emails and calls for help from new businesses.”

Peck is perhaps the foremost scientific expert in the country on cider apples and cider making. He is at the forefront of the cider renaissance and a large part of his research revolves around this emerging industry. “Cider apple growers and producers need a lot of technical support,” he says. “They need research to help them figure out which cultivars make the best cider, how to grow them, how to harvest them, how to store them. Those are the questions I’m trying to answer for the industry.”

Cider apples, a special breed

Cider makers urgently need apples – but not just any apple will do. All apples contain the sugar that is needed for fermentation, but cider made from sweet culinary apples such as McIntosh or Gala is much different than cider made from bitter cider apples, which have up to 10 times more concentration of polyphenols, or tannins. “Tannins are what give cider its astringency and bitterness,” Peck said. “It makes the difference between a sweeter style cider and one that is dryer with more mouthfeel, more lasting bitterness and astringency. That dry type of cider is what a lot of consumers want.”

Since the old cider cultivars that the settlers knew have disappeared from the American landscape, Peck and his collaborators are busy rediscovering them as well as finding new ones. In one project, Peck and graduate student Nathan C. Wojtyna, are sifting through the United States Department of Agriculture’s germplasm collection in Geneva, New York, trying to pinpoint apples that are suitable for cider making. About 3,500 different genotypes are in the collection, everything from modern culinary apples to wild species to ornamental hybrids. “We’ve whittled down the list to 350 that we’re particularly interested in,” Peck said. “It’ll probably take a couple of years to go through them all.”

The researchers harvest the apples from the target trees, take measurements for maturity, juice them, and then chemically analyze the components. “We’re quantifying polyphenols, acidity, sugar content, and other important attributes for the cider industry,” Peck said. “We hope to not only find cider apples that do really well in our New York climate but also to develop a suite of genetic markers for selection so that we and other research groups can find the cider apples of the future more quickly. After a few years, we hope to have a shorter list of potential genotypes for field plantings. Then we’ll see how they do in different sites and different climates.” As part of the project, Peck is also working with the Empire Cider Center in Geneva, a hard cider business incubation, testing, and production facility. He has provided Empire with apples from some of the most promising cultivars to make test batches of cider.

Growing cider apples

Finding the best cider apple cultivars is only the first step in maximizing quality cider production. “There are challenges to growing these specialized apples,” Peck said. “Managing the crop load is very important.” He has partnered with LynOaken Farms, a cider producer in Lyndonville, New York, in a project funded by the Apple Research Development Program to test the effects of different levels of crop load on the production of chemical compounds in the fruit. In the test, trees are thinned to low, medium, or high crop loads.

Findings from an earlier project showed that minimal thinning of the load resulting in more, smaller apples actually increases the polyphenol content in the cider by 37 percent after fermentation – a positive result for cider makers. At the same time, high crop loads tend to result in a lower amount of yeast assimilable nitrogen (YAN) in the apples, which is less desirable since fermentation yeast needs YAN for its metabolism. Further testing of crop load levels on eight European cider apple cultivars will help determine optimal thinning levels and lead to fermentation recommendations for cider producers.

Machine harvesting vs. hand harvesting

To support the growth of the industry, cider producers in New York have also asked Peck to research the mechanization of cider apple harvesting. Right now, most culinary apples in the United States are harvested by hand to avoid bruising the fruit. For cider apples that will be processed soon after harvest, bruising is less of a concern. “To stabilize the cider industry for the future, we need to ensure there’s an affordable production of these cider apples,” Peck said. “I believe strongly the way to do that is to mechanize these systems.”

Peck is researching the best orchard system that would allow machines to pick the apples. “In the spring of 2018, we’ll be establishing new plantings specifically designed to test mechanical harvesting systems,” he said. “We’ll set everything up for the machines: the spacing of the trees, the height of the trees, the types of trellises. We want them to be able to handle the rigors of the machine going through them. We’ll be looking at which apple cultivars are more amenable to mechanical picking, and we’ll test pruning techniques to find the best shape that allows machines to easily get to the fruit.”

Cider research, a collaborative venture

For his many cider research projects, Peck works with a wide range of colleagues across Cornell. He collaborates with Susan K. Brown, School of Integrative Plant Science, Horticulture/Plant Breeding and Genetics, to test potential cider apple selections. He works with colleagues at Cornell Cooperative Extension’s Harvest New York Program and the Dyson School of Applied Economics and Management, exploring the economics of the emerging cider industry. With researchers in food science, he studies the nuances of apple juice fermentation.

Peck has also developed an undergraduate cider production course with viticulture and enology lecturer, Kathleen J. Arnink in the Food Science Department. “Cornell is already known for our cider outreach programs,” he said. “Looking forward, I want Cornell to be the leader for cider research and teaching. We have the resources and talent to get a lot done for this emerging industry.”