Fermentation Science: Oregon State University

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1 Fermentation Science: Oregon State University Thomas H. Shellhammer Professor of Food Science Nor Wester Professor of Fermentation Science Daniel C. Sharp

2 Willamette Valley, Oregon

3 Training students to be brewers Photo s courtesy of Lynn Ketchum

4 OSU Pilot Brewery 2 BBL brewhouse, 6 CCV Photo s courtesy of Steve Werblow

OSU has a long connection to hops 1932 Oregon largest hop producing region in the world with 34,594 acres (14,000 ha) Downy Mildew discovered in Oregon hop yards U.

5 OSU has a long connection to hops 1932 Oregon largest hop producing region in the world with 34,594 acres (14,000 ha) Downy Mildew discovered in Oregon hop yards U.S. Department of Agriculture establishes hop breeding program 1979 Hop Research Council created 1996 Fermentation Science track created within Dept of Food Science

polyphenols Impact, time-intensity, quality Foam studies Bitterness Intensity

6 Shellhammer Lab Hops research, recent activity Isomerization kinetics Bitterness research Native and reduced iso-alpha acids Hop-derived polyphenols Impact, time-intensity, quality Foam studies Bitterness Intensity I max t max Tim e Area Duration Reduced iso s Flavor stability Hop-derived polyphenols Hop acids

7 Shellhammer Lab Hops research, current projects Investigating the sources of citrus aroma/flavor from hops Hop harvest maturity influences on oil quality Basic studies on dry hopping How hops affect beer flavor stability New methods for assessing beer bitterness

8 Shellhammer Lab Hops research, current projects Investigating the sources of citrus aroma/flavor from hops Hop harvest maturity influences on oil quality Basic studies on dry hopping How hops affect beer flavor stability New methods for assessing beer bitterness

9 Hop Aroma What is it? Where does it come from? How do I get it?

10 Harvest A line in the sand

11 Quality Quality is the indicator for the condition in which hop constituents are when being added to the beer/wort, i.e. the definition of quality indicates whether degradation took place from picking to dosage. Forster, A. The quality chain from hops to hop products. In 48th IHGC Congress, Canterbury, Barth-Haas Research & Publications ( barthhaas. com); The degree of reduction in quality can be described by a quantitative measurement of aging components (or correlated components).?????

12 Quality: A relative perspective

13 Assessing the aroma quality of hops Hop rubs and teas have limitations. Come up with at least one descriptor for each hop. Rank them in order of most preferred to least preffered.

14 Big Picture Quality Control Points Cultivation Harvest Kilning Conditioning Packaging Storage Heat, time, moisture and oxygen =

Principle Components Concentration (%w/w) Cellulose-lignins 40.0-50.0 Proteins 15.0 Alpha acids 2.0-17.0 Beta acids 2.0-10.0 Water 8.0-12.0 Minerals 8.0 Polyphenols and tannins 3.0-6.

15 Principle Components Concentration (%w/w) Cellulose-lignins Proteins 15.0 Alpha acids Beta acids Water Minerals 8.0 Polyphenols and tannins Lipids and fatty acids Hop oil Monosaccharides 2.0 Pectins 2.0 Amino acids 0.1 European Brewery Convention Hops and Hop Products, Manual of Good Practice; Getranke - Fachverlag Hans Carl: Nurnberg, Germany, What is it? Chemical Composition of Hops SEM Image of Lupulin glands Forster, A. The quality chain from hops to hop products. In 48th IHGC Congress, Canterbury, Barth-Haas Research & Publications ( barthhaas. com); NEED PERMISSION Kishimoto, T.; Wanikawa, A.; Kono, K.; Shibata, K. Comparison of the Odor-Active Compounds in Unhopped Beer and Beers Hopped with Different Hop Varieties. Journal of Agricultural and Food Chemistry 2006, 54, NEED PERMISSION

16 Concentration (ml/100g hops) Harvest Timing: Total essential oil content during hop maturation Harvest time point Mt. Hood Nugget Galena Willamette Adapted from: Murphey, J.; Probasco, G. The Development of Brewing Quality Characteristics in Hops During Maturation. MBAA TQ 1996, 33,

17 Harvest Date: Oil Content by Location Concentration (ml/100g hops) Cascade Oil volume at 8 % moisture 2010 Harvest Farm 1 Farm 2 Farm 3 Concentration (ml/100g hops) Willamette Oil volume at 8 % moisture Farm 1 Farm 2 Farm Early Typical Late Early Typical Late Harvest Time Point Harvest Time Point Difference exists between hops harvested at different locations.

18 Adapted from: Eyres, G.; Dufour, J. Hop Essential Oil: Analysis, Chemical Composition and Odor Characteristics. In Beer in Health and Disease Prevention; Preedy, V. R., Ed.; Academic Press: San Diego, 2009; pp

19 Composition Schönberger, C.; Kostelecky, T. 125th Anniversary Review: The Role of Hops in Brewing. J. Inst. Brew 2011, 117,

20 Principle Odor Compounds in Hops Spicy/Herbal Piney/Woody Floral Citrus Fruity/Tropical Epoxides Myrcene Nerol Limonene Linalool Eudesmol Beta-Pinene Geraniol Citral Esters Farnesol Alpha Pinene Geranyl Acetate Citronellol Caryophyllene Oxide Farnesene Linalool Caryophyllene Citronellol Sulphur Alpha Terpineol Compounds Humulene

21 Odor Active Compounds: Fresh Hops

22 Harvest Timing: Oil Profile Concentration (mg/100 g hops) Cascade Myrcene 0 Early Typical Late Harvest Time Point Howard, G.A., Slater, C.A. Effect of Ripeness and Drying of Hops on the Essential Oil. J. Inst. Brew. 1958, 64,

23 Aroma compound concentrations: Hallertau MF Concentration (µl/100g hops) Harvest time point Linalool Geraniol Humulene Epoxide II Hop oil contents increased an average of 30% from day -3 to day 21.. Adapted from: Bailey, B.; Schonberger, C.; Drexler, G.; Gahr, A.; Newman, R. The Influence of Hop Harvest Date on Hop Aroma in Dry-Hopped Beers. TQ 2009.

24 Indicators of Degradation 2010 Harvest Concentration (mg/100 g hops) Cascade isovaleric acid Concentration (mg/100 g hops) Willamette isovaleric acid Early Typical Late Harvest Time Point 0 0 Early Typical Late Harvest Time Point

Preliminary brewing: Cascade Orange Fruit Cocktail 7.0 6.0 Tropical fruit 5.

0 Grapefruit Typical Late Pine Estery (tutti fruitti) Green Hop Green Apple Floral Rose

25 Preliminary brewing: Cascade Orange Fruit Cocktail Tropical fruit 5.0 Sweaty/Onion/Garlic 4.0 Melon Apricot/Peach Grapefruit Typical Late Pine Estery (tutti fruitti) Green Hop Green Apple Floral Rose Typical harvest hops = apple, apricot/peach, and sweaty/onion/garlic notes. Late harvest hops = higher melon and floral notes.

26 Big Picture Quality Control Points Cultivation Harvest Kilning < 60 C Conditioning Humidity control Packaging Storage

27 Baling 80 kg bales Farmers bales SEM Image of Lupulin glands Forster, A. The quality chain from hops to hop products. In 48th IHGC Congress, Canterbury, Barth-Haas Research & Publications ( barthhaas. com); 2001.

28 Baling Forster, A. The quality chain from hops to hop products. In 48th IHGC Congress, Canterbury, Barth-Haas Research & Publications ( barthhaas. com); 2001.

29 Storage Temp

30 So what? Harvest timing matters. Changes in the amount and profile of hop oil. Baling Keep under 60 kg Storage Low temp (0 C) for < 1 year. Communicate with your customer. Sensory Result?

31 Acknowledgments Shaun Townsend, OSU OSU-USDA ARS Hops Group Indie Hops Goschie Farms Coleman Farms

Inside the brewery. How is beer made? Barley Malting. Hop Quality A Brewer s Perspective. Barley Water

Inside the brewery. How is beer made? Barley Malting. Hop Quality A Brewer s Perspective. Barley Water How is beer made? Hop Quality A Brewer s Perspective Thomas H. Shellhammer Ph.D. Nor Wester Professor of Fermentation Science Oregon State University, Corvallis, Oregon, USA Barley Water Hops Yeast Barley