Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
36 evans
1. Modernization of malt quality analysis to
better inform brewers, maltsters and
barley breeders - functional tests and
future opportunities
Dr Evan Evans
School of Plant Science
University of Tasmania
Australia
Australian Barley Biochemistry & Brewing Research
Barley Malting Quality … from Grass to Glass.
2. Introduction
• If it is not malting quality it is feed!
Big $ implications for grower profits - gross margins
• Malting quality specifications are the basis commercial
transactions in the malt quality value chain
• Good malt quality reduces maltster and brewer risk - $ premiums
Grower Grain trader Maltster Brewer
How accurately do current
malt quality specifications predict malt quality?
What is the malt quality risk premium? Can we lower it?
$$$
$$$
Lower risk
Higher risk
3. What does the brewer really want to know?
• How much does it cost?
• How consistent & predictable is the malt quality?
• How much beer will a tonne of malt make?
• Will there be any brewing/fermenting difficulties (ie PYF)?
• Will there be any production difficulties (ie lautering, filtration)?
• Will the beer quality match specifications (ie color, foam, flavor)?
A Typical Malt Quality Specification Report
“Functional” Malt Quality Specifications: Barry Axcell, SABMiller
4. 1. Mashing procedure - how relevant is the Congress mash?
2. Mash filtration performance: lautering and mash filter?
3. The value of spectrophotometric measures of malt quality ie NIR?
4. DP enzymes, individual testing and fermentability prediction?
5. Modification of proteins and non-starch polysaccharides?
6. Lipids, lipoxygenase, flavor and foam?
7. Microbial assessment, the good, the bad and PYF?
8. Beer clarity - haze
Malt Quality Specifications Considered
“New Malt Quality Specifications must be
“accurate” “rapid” and “cost efficient”
7. The influence of mash in
temperature on AAL and
sugar composition
5.7%
8. Grist grinding - disc mill vs 6 roller mill
Conclusion: Brewers consider 0.7mm grind “closer”
to reality
6 roller mill Disc mill with setting:
Commercial
grist
0.2 mm
grind
0.7 mm
grind
1.0 mm
grind
Sieve Proportions
1.25 mm 46.4% 2.1% 9.8% 27.2%
1.0 mm 8.5% 1.8% 14.6% 20.2%
0.50 mm 16.4% 9.1% 41.5% 24.1%
0.25 mm 9.5% 37.9% 13.0% 9.7%
0.125 mm 6.0% 17.1% 6.5% 5.2%
Pan 13.3% 32.1% 14.6% 13.7%
9. Grist Milling
Mash in 65°C 50 min,
1:4 ratio, finish 74°C,
0.22mM CaSO4
Conclusion:
Substantial impact,
select 0.7mm as closer
to brewers reality
10. Grist to water ratio
Mash in 65°C 50 min,
0.7mm grind, finish 74°C
0.22-0.3 mM CaSO4
Conclusion:
Grist : water important,
choose 1:3 as closer to
commercial practice
11. Mash duration
Mash in 65°C, 1:3 ratio
0.7mm grind, finish 74°C
0.3 mM CaSO4
Conclusion:
Mash duration important.
use 60min as this gives
close to max fermentability
and same as IoB protocol
17. As simple 25min test of lautering performance
A bolt on to mash extract evaluation
18. As simple 25min test of lautering performance
A bolt on to mash extract evaluation
19. The Value of Spectrophotometric
Measures of Malt Quality?
Such as NIR and IR
20. • NIR regularly used for grain/malt protein and moisture - good accuracy
• Wort and alcohol in beer (ie Anton Paar Alcolyzer - very accurate)
• Breeders use for culling of inferior lines for:
- whole grain (barley - ads and limits) vs whole malt
- extract
- DP/ -amylase
- -glucan / viscosity
- FAN and soluble protein
- parameters such as husk content and grain color
- LOX?
Spectrophotometric Measures of Malt Quality
Future?
• NIR and image analysis?
• IR combined with statistical evaluation - new opportunities?
- Lipids in wort?
• Other components?
35. Comparison of the fatty acid content & composition of the wort
produced by the Final 65°C mashing protocol for 12 Gairdner malts
and the original 8 varieties
36. Modification of proteins
and non-starch polysaccharides?
KI, FAN, wort -glucan, viscosity
Beer filtration (AAL and foam)
37. Proteins and proteases
• Provision of FAN for yeast nutrition
• Some proteins impact lautering and beer filtration (gel proteins?)
• Some proteins valuable for foam stability (protein Z, LTP1 etc)
Modification of proteins and non-starch polysaccharides
Non-starch polysaccharides and viscosity
• -glucan and arabinoxylan (if large) viscosity …. Lautering filtration
cross-flow filtration!
• Source of fermentable extract (glucose)?
• Soluble fibre (size - not too big, not too small)?
40. Microbes - more good than bad?
• We tend to focus on the bad, PYF, taints, gushing, toxins
However!
• Will not exclude as barley and malt is not sterile
• Produce beneficial enzymes, hormones
• Some may exclude harmful microbes
• Future: DNA - PCR testing for specific taxa?
Further discussion: Laitila A, More good than bad: microbes in the maltings.
Brewer & Distiller International, 2008, 4(8):52-54.
41. PYF
• Premature yeast flocculation (PYF) is an intermittent
fermentation problem.
• PYF results in incomplete wort fermentation.
• PYF occurrence appears to be related to certain malt
batches.
• However detection of problem batches is problematic
• Is a significant problem for some breweries.
See for further:
Evans, D.E. and Kaur, M. (2009) Keeping “Sleepy” Yeast Awake Until “Bedtime”:
Understanding and avoiding PYF The Brewer and Distiller International 5(5): 38-40.
42. The impact of PYF on fermentation
After van Nierop 2005 Thesis
46. Overall Classification of Varieties
SE -ve
varieties
17%
SE +ve
varieties
83%
SE +ve
Examples
Alexis
Arapiles
Baudin
Dhow
Franklin
Gairdner
Manley
Metcalfe
Optic
Scarlett
Schooner
Sloop
Steptoe
Triumph
SE -ve
Examples
Annabell
Barke
Bowman
Excel
Harrington
Haruna Nijo
Kustaa
Landlord
Moravian III
Morex
Pirkka
Robust
Saana
Unicorn
219 varieties were screened - 181 were identified as SE +ve,
while only 38 were identified as SE –ve.
47. Pilot Brewing Haze Stability Trial
55ºC Force Test
0
2
4
6
8
10
12
Unicorn
Harrington
Stiring
Schooner
Franklin
Gairdner
Variety
EBC
Haze
Units
SE (-)
SE (+)
The colloidal stability of beer produced from 6 (50L) pilot brewing trials with
the Tooheys chill haze force test (5 day 55oC/ 1 day 0oC).
Pilot brewing trial Sydney 2000 (50L)
48. Recent Novel Beer Haze Proteins?
(Iimure et al. 2008, J. Cereal Sci. Sapporo, Japan)
Haze growth factors (proteomics approach)
• Barley dimeric -amylase inhibitor (BDAI-I)
• BTI-CMb
• BTI-CMe
See also:
Robinson, et al. (2007) Journal of Cereal Science, 45:335-342 and 343-352.
49. Brewer
• Raw material more
predictable - consistent
• Less problems - waste
• Develop new products
User targets for improved malt quality specs
Maltster
• Customer satisfaction
• Reliability & consistency
• New targets….
sustainability
- reduce water use
- reduce energy use
Still provide good malt!
Barley
Breeder
• Select specific genes
• Customer satisfaction
- growers
- maltsters
50. Co-authors
Brian Rossnagel, Alex Speers, Mike Edney,
Sophie Roumeliotis
Assistance:
Very many people!
Funding:
Grains Research and Development Corporation,
Grant: UT 00017.
Acknowledgments