The document summarizes research on the proteins that contribute to beer foam formation and stability. It discusses three major proteins - Lipid Transfer Protein 1 (LTP1), Z4, and Z7. LTP1 is the main factor for foam production, becoming active when denatured during mashing. Z-proteins stabilize the foam. Factors like temperature, detergents, and alcohol content can affect foam. The proteins originate from barley and their levels are influenced by brewing conditions like mashing temperature. Quantifying foam helps analyze factors that influence it.

1. Kyle Breitinger
Mentor: Charles Coughlin
Moderator: Casey Zender
Bader, 2014

2. 
 Frothy collection of bubbles formed at the top of beer
 Also called beer head or froth
 Formed by interactions between proteins and gas
What is beer foam?

3. 
How is it made?
 Okayama University discovered
the three major proteins that
contribute to beer foam:
 Lipid Transfer Protein 1 (LTP1)
 Z4
 Z7
 Hydrophobic due to alpha-helical
folding
Blasco, 2011
U of U 2016
• Proteins surround gas bubble and
ride up to the surface
• Creates bubble lattice on top of beerBech, 1995

4. 
Where do these proteins
come from?

5. 
LTP1 is the main contributing
factor for beer foam production
 Globular form in raw barley
 Becomes denatured during
“mashing”
 Denatured form is active
Z-proteins are foam stabilizing
 Major factors in foam retention
How do these proteins affect
beer foam?

6. 
 Temperature (Foam +/-)
1. Mashing
2. Serving
 Due to CO2 solubility
 Detergents/lipids (Foam -)
 ABV (alcohol by volume) (Foam -)
 Etching in the glass (Foam +/-)
 Nucleation sites
What can affect beer foam?

7. 
Why do we want foam?
 Releases odor compounds (aromatic esters) to the
surface
 contribute to smell and taste of beer
 Acts as a Trigeminal sensation
 Due to Cranial Nerve IV (much like spicy
foods and mint)
 Foam means there is still carbonation in the
beer!
 When flat, beer will produce little to no foam
because of two reasons:
1. No gas means no foam
2. There is a limited supply of proteins
 It Makes for a great Mustache!
Theawesomer.com

8.  Foam measuring machine
 Mechanical sensor that follows the beer down the glass as
the foam decays
 This measures:
 How fast the foam deteriorates
 How much foam
How do you quantify beer
foam?

9.  Onshi and Proudlove, Japan: Looking to see what was in beer foam
 Used nitrogen to create foam
 The foam was then separated into two fractions through column
chromatography
1. High molecular weights
2. Low molecular weights
How did we find out about
these proteins?
Kai, 2013

10. 
The high molecular weight fraction:
 contained mostly carbohydrates
 10 percent protein (these proteins were the
two Z-proteins (Z4 and Z7))
The small molecular weight
fraction:
 Mostly proteins
 later found to be LTP1
What were their findings?
LTP1 molecular structure
Bech, 1995
Z- protein. EMBL 2015

11.  Van Nierop et al, South Africa
 Two South African breweries
(Brewery A and B)
 Asked to brew the same exact beers
using the same exact raw materials
 They were given identical sampling
time intervals
 Wanted to know:
 Any differences in the way they
make beer
 Would this affect beer foam
production?
How Denatured LTP1 Was
Found To Create Beer Foam
Samuel Adams, 2014

12. 
 Brewery B’s beer contained more foam and higher levels of
LTP1 (through ELISA) than Brewery A’s beer
 Brewery A was at an attitude of ~200 meters above sea level
 Brewery B was at an altitude of ~1800 meters above sea level
 Why does altitude matter?
 Brewery B is at a higher altitude which means they are
brewing at lower atmospheric pressure compared to
Brewery A
 Brewery A wort boiling ~ 102 Degree Celsius
 Brewery B wort Boiling ~ 96 Degrees Celsius
Results of South African
Brewing Experiment

13. 
Results of South African brewing
experiment (continued…)
Table 1 LTP1 levels measured via ELISA over the brewing process at breweries
A and B (Van Nierop et al, 2004)

14. 
Brewery B had higher LTP1 levels due to lower
temperatures and less denaturation
Brewery A had lower LTP1 levels due to proteins
being denatured to a greater extent to a non-
functional conformation
LTP1 was more effective at binding free fatty acids
when it is not fully denatured
Results of South African brewing
experiment (continued…)

15. 
Results of South African brewing
experiment (continued…)
Brewery B Brewery A
Van Nierop et al, 2004


16.  YES!
 Growing barley in drier climates helps produce more LTP1 in
the barley thus creating more beer foam when brewing
 Some scientists have taken pure mixtures of denatured LTP1
and tried to introduce it after fermentation. This created beer
foam that was very unstable and did not last long
 German scientists have spliced the gene encoding for LTP1
production into yeast cells. These cells then create LTP1
during fermentation increasing the concentration and causing
for more beer foam
Have we tried to brew
with more LTP1?

17. Foam Mug
 Creates bubbles that induce foaming
 Etched glasses (Guinness created a special
glass)
 Creates more nucleation sites = More foam
We have the devices to
create more foam!
Guinness, 2010

18. 1. LTP1 is the major protein involved in foam
production
2. Z4 and Z7 maintain beer foam stability
3. Without these proteins beer would not be as
enjoyable as it is with an aromatic full bodied beer
head
Conclusions

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70. Web.
Work Cited

20.  Gerritson, Vivienne B. "One Beer Please." Protein Spotlight The Full. SIB Swiss Institute of
Bioinformatics, 01 May 2004. Web.
 Halford, Bethany. "Four Tips for Getting the Best Beer Foam." Newscripts. Chemical and
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Britannica. Web.
 Lees, Michael A., Peter A. Rodgers, Duncan B. Campbell, Michael A. Pecar, and David C.
Shudarmana. "Intelligent Systems for the Brewery Based on Real-Time
Measurement of Biological Parameters." Australian Barley Technical
Symposium 53.1 (1999): 313-16. The Regional Institute.
 "Plant Lipid Transfer Proteins." Wikipedia. Wikimedia Foundation, 02 Dec. 2015. Web.
 Rudin, A. D. "Measurement Of The Foam Stability Of Beers." Journal of the Institute of
Brewing 63.6 (1957): 506-09.
 Veneri, Gianluca, Gianni Zoccatelli, Silvia Mosconi, Chiara Dalla Pellegrina, Roberto
Chignola, and Corrado Rizzi. "A Rapid Method for the Recovery, Quantification
and Electrophoretic Analysis of Proteins from Beer." Journal of the Institute of
Brewing 112.1 (2006): 25-27.
Work Cited Cont…

21.  Bader, Heinz Peter. Foam in Beer. 2014. Corbis, Seattle,
Washington.
 Bech, M. L. Barley LTP1 Molecule. 1995. European Brewery
Congress, Brussels.
 Blasco, Lucia. Foam Structure. 2011. Microbid International,
Barcelona, Spain.
 Santilli, Laura. Gene for Beer Foam. 2005. Fotolia, New York. Kai.
Yeast and O2. February 2, 2013. Braukaiser, Germany.
 Urie, Brendon. Guinness Mustache. 2011. Tumbler, Dublin,
Ireland.
 The Mo-Gaurd. Theawesomer.com, California.
 Vesicle. University of Utah. 2016. LearnGenetics.com
Picture Citations

22. 
Special Thank You