Final report for ONC17-030
Hard cider is the fastest growing craft beverage in the US. With the price for cider apples higher than dessert apples, less focus on the fruit's cosmetic appearance, and emerging networks of farmers interested in craft cider production, this nascent industry offers opportunities for increasing economic, environmental and social sustainability in the North Center Region. Unfortunately, inadequate information about cider apple varieties and market preferences limit growers ability to tap cider's potential.
The project tested 41 apple varieties with potential for sustainable cider production based on grower experience. Cider properties are assessed through lab and sensory evaluation. The study provides an artist's palette of promising cider apple varieties, and identifies a few flavor profiles that tasters rated highly.
Trees that produce specialty fruit for hard cider must be grafted. The project teaches people interested in hard cider and apple production how to graft, using scion from highly-rated varieties provided by cider farmers.
Identify 40 varieities with strong potential for hard cider production
Evaluate the cider properties of each variety through lab and sensory evaluation
Identify preferences for specific cider properties
Disseminate findings through a web site, conference presentations and field days
Conduct a scionwood exchange and grafting workshop
- (Educator and Researcher)
Student assistant Elly Voigt worked with growers to gather 41 varieties of hard cider apples, a bushel of each variety, from four orchards near Madison, Wisconsin. Our orchard-partners were: Albion Prairie Farm, Brix Cider, The Cider Farm, and Cider House of Wisconsin. Growers chose these 41 apples varieties because they had potential for horticultural and taste profiles. Farmers picked the apples when ripe, and we maintained the cold chain starting with harvest. Farmers stored the apples until we were able to bring them to the Food Science Lab at the University of Wisconsin-Madison.
Each variety was refrigerated until Nick Smith, UW-Extension brew master, and Cole Bielen, student fermentation assistant, pressed each variety and placed them into coolers to settle. After settling, the juice was racked off the lees, and 0.4 g/l of Superfood (BSG Wine) was added to the juice feed the yeast. The yeast used was 0.3 g/l of SafCider (Fermentis) rehydrated in 20 times its weight of water and 0.3 g/l Startup. The cider was then fermented at 60 degrees F for 2 weeks, and chilled to 35 degrees F to settle the yeast. The cider was racked off of the yeast lees, 40 ppm SO2 was added as a preservative, and it was bottled and stored at 41 degrees F. About a gallon of cider was produced from each variety.
The single-varietal hard cider was tested two ways to determine taste characteristics: in the lab and by panels of tasters. Before fermentation, the apple juice was tested for titratable acidity (MAE), brix, and pH. After fermentation, the cider was tested for total phenolics using the Folin-Ciocalteau reagent. Alcohol levels were not directly tested in this analytical analysis, but the perception of alcohol levels was identified in subsequent sensory tastings. To gather perception/ sensory data, four cider tastings were conducted among different demographics. Each of the 41 ciders was tasted at least once, and by at least 6 people, some more than that. Each tasting included a commercially-produced cider that served as a control. Each cider was assigned a randomized 3 letter code so that tasters wouldn't be influenced by the varietal names.
Our analytical results identified characteristics of each cider like phenolics, pH, and titratible acidity. The brix range was found to be between 10 and 18. The titratable acidity was found to be 1.6 g/L to 14.5 g/L, the pH range was 2.99 to 4.43, and the total phenolics was 361 to 3,021 GAE. The total phenolic content of the juice are compounds that contribute to astringency, mouthfeel, bitterness, and color.
Alcohol levels were not directly tested in this analytical analysis, but the perception of alcohol levels was identified in subsequent sensory tastings.
To gather perception/ sensory data, four cider tastings were conducted among different demographics. Each cider was assigned a randomized 3 letter code so that tasters wouldn't be influenced by the varietal names. All ciders were tasted by at least 6 people, some by more.
Dr. Julie Dawson and her lab organized the initial and most comprehensive tasting. It involved twenty people, including 5 growers. In this tasting, all 41 varieties were tasted, 12-16 by each taster. Each cider was tasted by at least 6 different people. Dawson ran the results and mapped them by flavor. The top left quadrant is bitter, while the bottom left quadrant is sweet. The top right quadrant is astringent while the bottom right is acid. SARE.cider_.PCAflavor
The second tasting was with Dawson's Seed to Kitchen Collaborative. Most of the tasters were either associated with restaurants or farms involved in the collaboration. Only 12 ciders were tasted, including a "check" commercial variety. These varieties were chosen among the 41 based on the analysis performed on the data collected at the first tasting. The varieties we chose to collect more data on were ones that more or less represented different levels of the four main flavor traits (astringency, acidity, bitterness, and sweetness.) This was so we could gather data not only on the specific varieties themselves, but also on flavor preferences / levels of each of the flavor characteristics.
The third tasting was at the WI Fresh Fruit and Vegetable Conference, with seventeen participants. Many of them had an interest in growing apples or were involved in growing grapes and making wine. The final tasting engaged employees at Willy St Co-op in Madison, WI. Seventeen people participated in this tasting. We chose specific varieties among the 41 for both of these tastings. Dawson also invited the participating cider farms to submit finished, commercially-available ciders for another tasting with her Seed to Kitchen Collaborative in April.
Dawson applied Principle Component Analysis to lab and tasting data so that we could visualize the relationships of the 41 varieties. Lab tests are easier and less expensive than sensory analysis. We wanted to see if there were correlations between the two types of tests, especially since taste can vary from year to year, orchard to orchard. She graphed both the laboratory and sensory variables on the same chart. The contribution of the lab (phenolics, ˚Brix and TA) and sensory (sweetness, acidity, bitterness, astringency) variables are balanced by giving each set equal weight in the analysis. This approach allows us to compare lab results on each apple variety with tasting results. We see in comparison that lab results may serve as a proxy for taste characteristics. Phenolics and ˚brix are perceived as astringency, bitterness and alcoholic strength. TA is perceived as acid. Of the 41 samples, Dabinette was the only cider that was perceived as more acidic than would be indicated by its TA. It had a high ˚brix (18), and high phenolics (2256). TA measured 1.6. We think this is a result of how flavors interact. These final graphs and an explanation of the results is illustrated on our project poster, available on this web site.
We also compared the same apple variety from two different orchards. The differences illustrated within a single variety from different locations mean that more research and long-term testing will be needed to draw firm conclusions about cider apple varieties. In the meantime, lab testing juice gives growers an inexpensive way to describe their product to cider makers or to make hard cider to their own specifications. A report detailing these results is forthcoming and will be available for free download on our web site. A second report that describes each variety, including photos of the apple variety, will also be available.
With data collected from our tastings and from our preliminary analysis, farmers supplied some specific varieties, as available, to use in our grafting workshop. This event was April 21, 2018, was free and open to the first fifty people to register. The Raboins, Dr. Amaya Atucha, and greenhouse manager Johanna Oosterwick taught grafting techniques. Attendees took home grafted apple trees that we identified as high overall and/or with high intensity ratings in our analysis. The project and the workshop were featured in a cover article of the CALS quarterly magazine Grow. https://grow.cals.wisc.edu/departments/features/craft-ciders-comeback
Educational & Outreach Activities
Matt Raboin (farmer/cider maker), Nick Smith (academic staff cider maker at UW Fermentation Lab), Michelle Miller (academic staff at UW-CIAS), and recent forestry graduate Elly Voigt presented on the project at the Wisconsin Fresh Fruit and Vegetable Conference in the Wisconsin Dells. There were about 25 people who came to the talk, and we sent our slideshow presentation to SARE to post on their website. Many of the people who came to the talk were orchardists, some made hard cider, and some were winegrape growers. Many were interested in the idea of our single-variety tasting. We showed our preliminary results, and let people know about the reports we are planning on creating and when/ where those would be available. We also conducted a tasting at that conference with 19 attendees. Michelle presented at the Great Lakes Fruit Expo in December 2018 to an audience of about 100 fruit growers. She was part of a panel that shared current work on apple production for hard cider specifically. In February 2019, Michelle attended the National Association of Cider Makers conference in Chicago and shared a poster on the project with about 50 farmers and cider makers. Overall attendance at the conference was over 1000 and attending made it possible to take extensive field notes on the needs and concerns of craft cider makers.
We prepared two reports: an overall report of the project, with our process and results across all varieties (expected print date December 2019, with free download available at www.cias.wisc.edu); and an educational fact sheet, where we focus in on each variety, with images, horticultural notes from the growers, analytical lab results, and text responses from our tastings describing flavor, mouthfeel, etc. of a cider made from only that variety (available at www.cias.wisc.edu). We aim to help people interested in growing, or expanding their growing, of hard cider apples identify which apples they would like to grow, and what each may add to a finished, mixed cider product.
Building on our experience with SARE-funded research, we are looking at the economics of hard cider supply chains funded with USDA-AFRI small farms grant, which kicked off in November 2018. We are working with faculty at Washington State University, Michigan State University, and University of Vermont. Part of UW's work is to bring together hard cider growers to share resources, teach and learn, and support each other. Brix and the Cider Farm are both serving as advisors to this project.
Learning about different apple varieties and their characteristics; discussing cider production with a master fermentation specialist; learning how to graft scionwood
This project put us in touch with a number of production scientists in North America who are investigating ways to more profitably grow apples for hard cider. There is talk of networking production scientists and adding social scientists to the network, too. This is critical since a supply chain approach to hard cider is necessary to find ways for farmers to negotiate fair prices for their products.
The SARE-funded work informed our next grant on supply chain and made it possible for us to make that leap.
There are a number of cider apples that fall in the mid-range of flavor. Growers who make their own cider may want to choose varieties from this cohort to make a base juice, and then choose apples with a more distinct flavor profile to blend and enhance the finished product. Apples with a higher intensity flavor may be worth growing, even if the trees don't produce as much fruit as other varieties. Apple flavor is highly variable from year to year, orchard to orchard, so think of our results as a snapshot of apples grown in the Upper Midwest, 2017. Lab test the varieties you are currently growing and share your results with other growers.
We recommend that growers lab test apple juice and use the findings to market their juice, if they are not making cider themselves. In this way, they can communicate quality and value to cider makers, and negotiate higher price points for their products.
- Apples for Artisan Cider with Michelle Miller and Matt Raboin (Multimedia)
- Lab measures as a proxy for sensory testing hard cider (Conference/Presentation Material)
- Comparing Apples to Apples: Single Varietal Hard Apple Cider Testing (Book/Handbook)