How Craft Beer is Transforming the Way We Think About Hops & Hop Flavor

How Craft Beer is Transforming the Way We Think About Hops & Hop Flavor Thomas H. Shellhammer Oregon State University Department of Food Science and Technology

The elements of this talk What is craft beer? How has craft beer affected the brewing supply chain Hop-forward beers are changing how we evaluate hop flavor Non-volatile components increase in number and complexity Controlling hop aroma the new holy grail.

Chemical Composition of Hops Principle Components Concentration (%w/w) Cellulose-lignins 40.0-50.0 Protein 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 3.0-6.0 Lipids and fatty acids 1.0-5.0 Hop oil 0.5-3.0 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, 1997.

Global beer and hops production Barth Haas Report 2014

Traditional view of global hops supply vs demand Barth Haas Report 2014

What is craft beer?

Market segments as defined by the Brewers Association Microbreweries Brew less than 15,000 BBL per year Brewpub Restaurant-brewery with >25% of beer sold on site Regional brewery 15,000 6 Million BBL per year Regional Craft Brewery A regional brewery producing >50% all malt beer or adjuncts used to enhance and not lighten flavor. Craft Beer Small less than 6 million BBl Independent (at least 75% independently owned) Traditional

Annual U.S. Production (US Bbl) U.S. Brewing Large vs small brewers 120000000 100000000 80000000 60000000 40000000 20000000 0 ABI MillerCoors Yuengling Boston Beer Co. Sierra Nevada New Belgium Brewing Co. Brewing Co. Gambrinus Lagunitas Brewing Co. Deschutes Brewery

Annual US Production (US Bbl) U.S. Brewing Large vs small brewers 2,500,000 2,000,000 1,500,000 1,000,000 500,000 0 Boston Beer Co. Sierra Nevada Brewing Co. New Belgium Brewing Co. Gambrinus Lagunitas Brewing Co. Deschutes Brewery

Number of breweries, 1870 Present Tremendous growth in U.S. as a result of craft brewery startups http://www.brewersassociation.org/statistics/number-of-breweries/

Brewpubs/Microbreweries drive growth of craft http://www.brewersassociation.org/statistics/number-of-breweries/

https://www.brewersassociation.org/statistics/national-beer-sales-production-data/

Long term trends in craft brewing Chuck Skypeck, Brewers Association

U.S. craft beer growth, 2001-2013 Chris Swersey, Brewers Association

Craft beer is growing but overall U.S. beer growth is flat Chris Swersey, Brewers Association

Hop usage (g/hl) U.S. Craft brewers are using more and more hops 750 Hop usage (g/hl) 700 650 600 550 500 450 400 2008 2010 2012 2014 2016 Year Adapted from Brewers Association

Hop usage (g/hl) U.S. Craft brewers are using more and more hops 800 Hop usage (g/hl) 700 600 500 400 300 200 100 0 2008 2010 2012 2014 2016 Year Adapted from Brewers Association

Hop usage (g/hl) U.S. Craft brewers are using more and more hops Hop usage (g/hl) 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 2008 2010 2012 2014 2016 Year Adapted from Brewers Association

How is this growth impacting farming?

U.S. aroma hop acreage has increased significantly Chris Swersey, Brewers Association

Where is growth in U.S. hop varieties? 250% % Acreage Change '12-'13: Craft Hops vs CTZ 200% 150% 100% 50% 0% -50%

U.S. farmers are investing and growing

How does the growth in demand impact breeding?

Hops breeding takes time and enormous effort Year 1: Parental selection and crossing Based on breeding objectives Year 2: Early selection Start 40,000 10% selection rate End 4000 Years 3,4,5: Intermediate selection Start 4,000 1% selection rate End 40 Year 11+: Commercialization Years 9,10,11: Elite Trials Overall rate: 0.005% Start 2 Selection rate:? Years 6,7,8: Advanced selection Start 40 3% selection rate End 1.2 Jason Perrault, Select Botanicals Group

Hop Breeding Objectives Moving Towards Aroma Alpha/Bitter Processed hops. Yield measured in Kg. Alpha/acre Typically high alpha varieties, increasingly aroma. Aroma Minimal processing. Yield measured in lb/acre Typically aroma varieties, some high alphas.

D2 (20.86 %) Brewers flavor expectations of hop varieties PCA of responses D1 vs. D2 5 Biplot (axes D1 and D2: 53.76 %) after Varimax rotation 4 Apollo Musty Summit 3 2 East Kent WoodyGrassy Golding Leather Tobacco Fuggle Millenium Onion/Garlic (CTZ) Columbus/Tomahawk/Ze us 1 0-1 Spalter Galena Brewer's Gold Styrian Golding Northern Brewer Spicy Herbal Palisade Chinook Cluster Willamette Saaz Ahtanum Nugget Tettnanger Magnum Perle (German origin) Hallertau Tradition Herkules Floral Spalt Select Perle (US origin) Hallertau MittleFreuh Tropical fruit Citrus Fruity Hallertau Taurus Simcoe Amarillo Nelson Sauvin Citra Cascade -2-6 -5-4 -3-2 -1 0 1 2 3 4 5 6 D1 (32.90 %)

Nelson Sauvin Amarillo Cascade Citra Ahtanum Palisade Willamette Herkules Simcoe Chinook Hallertau Taurus Perle (US origin) Hallertau Tradition Perle (German origin) Hallertau MittleFreuh Spalt Select Tettnanger Styrian Golding Saaz Summit CTZ Apollo Millenium East Kent Golding Fuggle Spalter Magnum Cluster Galena Brewer's Gold Nugget Northern Brewer Dissimilarity Cluster analysis yields 4 groups 120 100 80 60 40 20 0

Group characteristics and varieties Group Floral Fruity Tropical fruit Citrus Herbal Spicy Grassy Woody Onion/Gar lic Musty Leather Tobacco 1 2.847 3.292 2.843 3.653 1.673 1.766 1.298 0.526 0.461 0.252 0.200 0.183 2 2.565 1.881 1.128 1.933 2.622 2.461 1.825 1.245 0.696 0.416 0.388 0.418 3 2.078 2.112 1.918 2.665 2.138 2.199 2.011 1.417 2.769 1.237 0.489 0.503 4 2.063 1.480 0.725 1.391 2.280 2.147 1.891 1.513 0.637 0.779 0.633 0.604 Group 1 Group 2 Group 3 Group 4 Citrus Herbal Grassy Woody Fruity Spicy Onion Tobacco Floral Floral Musty Leather Cascade Simcoe Summit Millennium Citra Chinook CTZ Nugget Amarillo Ahtanum Apollo Galena Nelson Sauvin Herkules Northern Brewer Hallertau Taurus Brewer's Gold Styrian Golding Palisade Willamette Perle (US origin) Spalt Select Hallertau Tradition Tettnanger Hallertau MittleFreuh Saaz Perle (German origin) East Kent Golding Magnum Cluster Spalter Fuggle

Where is growth in U.S. hop varieties? 250% % Acreage Change '12-'13: Craft Hops vs CTZ 200% 150% 100% 50% 0% -50%

How does the growth craft beer impact how we think about and measure hop flavor?

CCV Hop-forward beers are created using late and dry hopping and unique varieties Factors Hopping Regime (Kettle, Whirlpool, Dry-hop) Hop Cultivar (Simcoe, Hallertau Mittlefrueh) Yeast (ale vs lager) Response Chemical (Volatiles) Sensory (Descriptive Analysis) Kettle Whirlpool 60 minute boil ~100 C, 10 min 18 C, 48 hours Daniel Sharp, 2014

Hopping regime and hop variety interact Daniel Sharp, 2014

Annual US Production (US Bbl) Craft brewers top brands are hop-forward 2,500,000 2,000,000 1,500,000 1,000,000 500,000 0 Boston Beer Co. Sierra Nevada Brewing Co. New Belgium Brewing Co. Gambrinus Lagunitas Brewing Co. Deschutes Brewery

Thermal isomerization of alpha acids produces iso-alpha acid bitterness Low solubility Low bitterness High solubility High bitterness

Iso-a acids

Before HPLC there was counter current extraction or separation Link

Counter current extraction

The IBU Analysis Liquid-Liquid extraction of bitter compounds from beer Beer Strong Acid Non-Polar Solvent Bitter compounds Iso alpha acids Oxidized hop acids Polyphenols Non-bitter compounds Alpha acids + Adds excess hydrogen ions to solution protonating all carboxylic acid functional groups + When functional groups are protonated at a lower ph molecules decrease in polarity 3 N Hydrochloric Acid 2,2,4 trimethylpentane

The IBU Analysis Measure the absorbance at 275 nm Absorbance @275 x 50 = Bittering Units 1 BU 1 ppm iso-alpha acid

BU correlates with bitterness and iso-alpha acids concentrations at low hopping levels

Bitterness Units Correlation between total IAA & IBU 16.0 14.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Iso-alpha acids (ppm) via HPLC

Lightly kettle hopped beer

Bitterness Units Sensory Bitterness Sensory bitterness tracks BU/IAA 16.0 14.0 7.0 6.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 5.0 4.0 3.0 2.0 1.0 0.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Iso-alpha acids (ppm) via HPLC

Bitterness Units Correlation between total IAA & IBU @ higher levels 90.0 80.0 70.0 y = 1.2x + 2.0 R² = 0.906 60.0 50.0 40.0 30.0 20.0 10.0 0.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 Iso-alpha acids (ppm) via HPLC

Bitterness Units Correlation between total IAA & IBU 90.0 80.0 70.0 y = 1.2x + 2.0 R² = 0.906 60.0 50.0 40.0 30.0 20.0 10.0 0.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 Iso-alpha acids (ppm) via HPLC

Bitterness Units Sensory Bitterness Sensory bitterness does not track BU/IAA 90.0 14.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 Iso-alpha acids (ppm) via HPLC

Heavily dry-hopped beer

Another potential source of bitterness hop polyphenols Extraordinarily diverse group of compounds found in all plant material. a b c Characterized by a number of aromatic rings with numerous substituted hydroxyl groups. Polyphenols are highly reactive, easily oxidized and polymerized into high MW tannins. d g h e f a. (+)-catechin b. (-)-epicatechin c. (-)-epigallocatechin d. Procyanidin B3 e. Prodelphinidin B3 f. Procyanidin C2 g. quercetin h. kaempferol i. xanthohumol j. isoxanthohumol i j

a and b acid oxidation a acid - Humulone Iso-a-acid iso humulone b acid - Lupulone

a and b acid oxidation a acid - Humulone Iso-a-acid iso humulone b acid - Lupulone Oxidation Oxidized alpha acid Humulinone Oxidized beta acid Hulupone

a and b acid oxidation a acid - Humulone Iso-a-acid iso humulone b acid - Lupulone Oxidation Oxidized alpha acid Humulinone Algazzali, 2014 Oxidized beta acid Hulupone

Commercial beer survey 10 Lagers 4 Amber-Reds 4 Pale Ales 4 IPAs humulinones 5 of 10 4 of 4 4 of 4 4 of 4 hulupones 0 of 10 2 of 4 2 of 4 3 of 4 22 17 7 Algazzali, 2014

Commercial beer survey humulinones average (mg/l) hulupones average (mg/l) Lagers (10) 1.3 (0-4.4) 0.0 Amber/Red (4) 14.4 (1.7-39.9) 2.0 (0-6.8) Pale Ale (4) 8.2 (3.0-12.9) 0.8 (0-1.7) IPA (4) 20.7 (11.7-27.9) 1.8 (11.7-27.9) Algazzali, 2014

Example: Amber-Red 2 70 60 62.5 50 40 39.9 30 20 21.6 10 6.8 0 BU iso-α-acid (ppm) humulinone (ppm) hulupone (ppm) Algazzali, 2014

Example: Amber-Red 2 70 60 62.5 50 40 30 20 41% 21.6 49% 26.0 10 10% 5.6 0 BU iso-α-acid (bitterness) humulinone (bitterness) hulupone (bitterness) Algazzali, 2014

With hop forward beers Does controlling aroma matter? How does a brewer control aroma intensity or quality? Does total hop oil content matter?

Conceptual approach does oil amount matter Control Whole Cone Cascade C 1 1 lb/barrel Washington Oregon Farm 1 Farm 2 Farm 3 Farm 1 Farm 2 1 2 3 n R 2 Vollmer, 2015 Primary Factors: Oil Content (15 unique oil contents) Oil Composition Secondary Factors: Region (Washington, Oregon) Location (WA 2) (OR 2) Farm (WA 3) (OR 2) Harvest Dates (Aug 14 Sept 22) Kiln Type, Time, Temperature

2272_1 2292_1 3000_1 3000_2 2434_1 2397_1 2471_1 3008_1 2380_1 2316_1 2605_1 3034_1 2418_1 2295_1 2432_1 2356_1 2406_1 2580_1 2610_1 2634_1 3305_1 3305_2 2414_1 2678_1 3056_2 3128_1 3128_2 3056_1 Total Oil Content (ml/100g) Cascade Hops with varying total oil content 2.5 2.0 1.5 1.0 0.5 0.0 Lot ID OSU Total Oil Content Vollmer, 2015

2272_1 2292_1 3000_1 3000_2 2434_1 2397_1 2471_1 3008_1 2380_1 2316_1 2605_1 3034_1 2418_1 2295_1 2432_1 2356_1 2406_1 2580_1 2610_1 2634_1 3305_1 3305_2 2414_1 2678_1 3056_2 3128_1 3128_2 3056_1 Total Oil Content (ml/100g) Overall Hop Aroma Intensity Cascade Hops with varying total oil content 2.5 10.00 2.0 9.00 1.5 8.00 1.0 7.00 0.5 6.00 0.0 5.00 Lot ID OSU Total Oil Content OHAI Vollmer, 2015

mg/100g of hops The usual suspects may not matter Myrcene Linalool 1800 16 1600 1400 y = 74.3x + 235.3 R² = 0.031 14 12 y = -0.46x + 10.737 R² = 0.019 1200 10 1000 8 800 600 6 400 4 200 2 0 5 6 7 8 9 10 OHAI 0 5 6 7 8 9 10 OHAI Vollmer, 2015

Conclusion Beware of brewing dogma Challenge conventional wisdom with science Adapt

Acknowledgements Victor Algazzali Jeff Clawson Daniel Sharp Dan Vollmer Philip Wietstock