Fermentation Science at Oregon State University

Thomas H. Shellhammer

Professor of Food Science Nor’Wester Professor of Fermentation Science

Food Science & Technology

OSU Seafood Laboratory - Astoria

Wiegand Hall - Corvallis

Food Innovation Center - Portland

Changing the future. Right here. Right now.

Tapping talent:

With one of the nation’s only teaching breweries and an endowed chair in fermentation science, OSU o!ers students the opportunity to develop new brews while they learn the subtle chemistry of taste and the innovations of business. Jobs on tap.

Agriculture is where food begins. Learn more at agsci.oregonstate.edu/foodies

Oregon bubbles to the top of the craft beer industry

B.S. Degree in Food Science and Technology Ø  Food Science 30% Ø  Fermentation Science 50% Ø  Enology & Viticulture 20%

OSU Food Science Undergraduate Degree Program

Undergraduate enrollment

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Enrollm

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Academic  year  (beginning  in  Fall)  

Training students to be brewers

Photo’s courtesy of Lynn Ketchum

Training students to be brewers

Photo’s courtesy of Lynn Ketchum

Employers of OSU Ferm. Sci. Grads

Anheuser-Busch Bridgeport Brewing Block 15 Cascade Lakes Brewing Craft Brewers Alliance Deschutes Brewery Full Sail Brewing McMenamins’ MillerCoors Rogue Ales

Adelsheim Winery Champoeg Cellars St. Michele Winery Gallo Winery

(Sonoma Valley, CA) Hogue Cellars King Estate Winery Tillamook County Creamery Rogue Creamery Tumalo Farms

Fermentation Science at OSU

•  Brewing •  Barley breeding & malting – Pat Hayes •  Hops breeding – Shaun Townsend & John Henning •  Hops pathology – Dave Gent •  Hops & health – Fred Stevens •  Wine – James Osborne & Elizabeth Tomasino •  Cheeses & dairy – Lisbeth Goddik •  Cereals chemistry & bread – Andrew Ross

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

OSU Minimalter

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 –  Comparisons among reduced iso’s

•  Flavor stability –  Hop-derived polyphenols –  Hop acids

Bitt

erne

ss In

tens

ity

Time tmax

Imax Area

Duration

Sensory testing Consumer as well as trained panel

Survey results using professional brewers Hop contributions to beer flavor

Cascade Citra

Amarillo    

Simcoe®

Summit    

Chinook

Nelson  Sauvin    

(CTZ)  Columbus/Tomahawk/Zeus    

Ahtanum    

Herkules    

Hallertau  Taurus    

Millenium    

Styrian  Golding    

Apollo    

Nugget    

Galena    

Palisade®    WillameOe  

Perle  (US  origin)    

Northern  Brewer    

Spalt  Select    Hallertau  TradiSon    

TeOnanger    

Brewer's  Gold    

Hallertau MittleFreuh

Saaz

Perle  (German  origin)    

East Kent Golding

Magnum    

Cluster    

Spalter    

Fuggle    

Floral  

Fruity  

Tropical  fruit  Citrus  Herbal  

Spicy  

Grassy  Woody  

Onion/Garlic  

Musty  

Leather  Tobacco  

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-1

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-­‐6   -­‐5   -­‐4   -­‐3   -­‐2   -­‐1   0   1   2   3   4   5   6  

D2

(20.

86 %

)

D1 (32.90 %)

Biplot  (axes  D1  and  D2:  53.76  %)  aCer  Varimax  rotaEon  

Shellhammer Lab Hops research, current projects

•  Investigating the sources of citrus aroma/flavor from hops

•  Hop maturity influences on oil quality

•  Basic studies on dry hopping •  How hops affect beer flavor

stability •  New methods for assessing

beer bitterness

Shellhammer Lab Hops research, current projects

•  Investigating the sources of citrus aroma/flavor from hops

•  Hop maturity influences on oil quality

•  Basic studies on dry hopping •  How hops affect beer flavor

stability •  New methods for assessing

beer bitterness

A Study of Factors Affecting the Extraction of Flavor When Dry Hopping Beer

Dry hopping – experimental design

Instrumental Analysis

–  Beer brewed specifically for this project (5.1% EtOH v/v, 21 ppm Iso-α-acids)

–  Dry hopped for 12 days –  SPME/GC, HPLC, and UV Spec analysis –  Cold extraction, 4 C –  Samples taken at 2 hours, 4 hours, 6

hours, 24 hours, 4 days, 7 days, 12 days.

Sensory Analysis

–  Same beer (samples taken side by side) –  Sampled at 6 hours, 24 hours, 4 days,

12 days –  Trained sensory panel (11 individuals, 3

females 8 males) –  3 training sessions, 4 testing sessions –  Categories scaled on a 0-15 point scale –  Examined aroma and bitterness

Form - whole cones vs. pellets (Cascade from same farm and harvest time) Extraction - passive contact vs. stirring

Dry Hop Method

•  The dry hop treatments were conducted in 3.5 hL (3 bbl) stainless steel CCVs

•  90 Gallons (340 Liters) of beer in each treatment

•  1 lb/barrel (386g/hL) hops used for each treatment

•  One CCV utilized a centrifugal pump for stirring

Overall hop aroma intensity

Sample

Overall  Intensity

(panelist  mean  value)

Groups

SSrred,  4  days 9.432 A    

SSrred,  12  days 9.227 A

SSrred,  24  hours 8.591 A B

SSrred,  6  hours 7.614 B

Passive,  4  days 5.750 C

Passive,  6  hours 5.545 C

Passive,  12  days 5.205 C

Passive,  24  hours 5.023     C

Bitterness intensity

Sample

BiOerness  Intensity (panelist  

mean  value) Groups

SSrred,  12  days 9.932 A      

SSrred,  4  days 9.773 A

SSrred,  24  hours 8.568 A B

SSrred,  6  hours 7.614 B C

Passive,  24  hours 6.250 C D

Passive,  4  days 6.136 D

Passive,  12  days 5.932 D

Passive,  6  hours 5.659       D

Results

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Concen

traS

on  (m

g/L)  

Time  (hours)  

Whole  Hops,  SSrred   Whole  Hops,  Passive   Pellet  Hops,  SSrred   Pellet  Hops,  Passive  

Linalool

Results

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Concen

traS

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g/L)  

Time  (hours)  

Whole  Hops,  SSrred   Whole  Hops,  Passive   Pellet  Hops,  SSrred   Pellet  Hops,  Passive  

Myrcene

Results

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Concen

traS

on  (m

g/L)  

Time  (hours)  

Whole  Hops,  SSrred   Whole  Hops,  Passive   Pellet  Hops,  SSrred   Pellet  Hops,  Passive  

Myrcene – First 6 hours

Results

Compoun

d 6 Hours,

Passive 6 Hours,

Stirred Peak,

Passive Peak,

Stirred Final,

Passive Final,

Stirred

Myrcene 0.5% 2.6% 2.4% 5.6% 1.0% 4.0% Limonene 40.7% 41.8% 42.7% 52.2% 17% 30.8% Linalool 6.8% 9.0% 28.7% 48.5% 21% 48.5% Humulen

e 0.5% 1.1% 0.94% 0.9% 0.15% 0.64%

Geraniol 70.3% 57.3% 70.3% 119% 50.3% 91.0%

Compou

nd 6 Hours,

Passive 6 Hours,

Stirred Peak,

Passive Peak,

Stirred Final,

Passive Final,

Stirred Myrcene 8.4% 19.9% 9.7% 37.2% 5.9% 25.8% Limonen

e 43.1% 69.1% 43.1% 82.4% 39.5% 75.2%

Linalool 55.6% 89.2% 57.2% 100.7% 56.1% 90.6% Humulen

e 1.3% 8.3% 1.3% 17.1% 1.2% 14.2%

Geraniol 90.8% 105.2% 97.1% 117.9% 97.1% 102.9%

Results

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Polyph

enol  Con

centraSo

n  (m

g/L)  

Time  (hours)  

Whole  Hops,  Passive   Whole  Hops,  SSrred   Pellet  Hops,  Passive   Pellet  Hops,  SSrred  

Hop Derived Polyphenols

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α-­‐acid  con

centraSo

n  (m

g/L)  

Time  (hours)  

Whole  Hops,  Passive   Whole  Hops,  SSrred   Pellets,  Passive   Pellets,  SSrred  

α-acids

Conclusions

•  The stirred treatment yielded more overall aroma intensity, bitterness, and astringency relative to the unstirred treatment

•  As expected, α-acid concentration did not correlate to increased bitterness even though significant extraction occurred –  Polyphenol extraction did correlate to increased bitterness

Shellhammer Lab non-hop-related current projects

•  Fermentation performance studies •  Sour beer characterization

Methylsulfonylmethane & Fermentation

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Gra

vity

(°B

rix)

Cel

l Cou

nt (C

ells

/ml)

Time (Hours)

Gravity  and  Cell  Count  106,  0%  MSM  

Cell Count

Gravity

Standard (Normal) pitching rate

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10^6, 0.75% MSM 0.25% MSM

Underpitched

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Gra

vity

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10^5, 0.25% MSM

10^5, 0.5% MSM

10^5, 0.75% MSM 0.25% MSM

Underpitched

0.00E+00

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Cel

l Cou

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ells

/ml)

Time (Hours)

Yeast Cell Count

10^5, 0% MSM

10^5, 0.25% MSM

10^5, 0.5% MSM

10^5, 0.75% MSM

0.25% MSM

Sensory Evaluation of Belgian and US Red/Brown Sour Beers

•  13 Commercial Red/Brown Sour Beers

–  6 Belgian (Flemish) procured via importer –  7 US Craft (West, Midwest, East Coast) donated from

US breweries •  Instrumental Analysis •  Sensory Descriptive Analysis

Methods Instrumental Analysis

•  Organic Acids •  Acetate and Lactate •  Esters •  Higher Alcohols •  Volatile Phenols •  Fatty Acids •  Iso alpha acids

•  Apparent Extract •  Real Extract •  Alcohol by Volume •  Real Degree of

Fermentation •  pH •  Color •  Bitterness Units

Volatile Phenols

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4-Ethyl Guaiacol

American Belgian 0

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PPB

4-Vinyl Guaiacol

American Belgian 0

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4-Ethyl Phenol

American Belgian

meaty, smoky, clove, apple wood smoked bacon

-  medicinal, rubber, Band-Aid

Measurement   American   Belgain   t-­‐test  unequal  variance  

4-­‐ethyl  Guaiacol  (ug/L)  (ppb)   1293   657   0.083  

4-­‐vinyl  Guaiacol  (ug/L)  (ppb)   152   93   0.090  

4-­‐ethyl  Phenol  (ug/L)  (ppb)   616   241   0.049  

}

Cluster Analysis of Sensory Data

Questions?