A Look at Opposing Forces for Malt Quality Demands and Challenges

A Look at Opposing Forces for Malt Quality Demands and Challenges Xiang S. Yin Rahr Corporation, USA June 25-28, 2017

Contents Introduction Barley: Quality integrity and supply assurance - Continuous battles against mycotoxins, gushing, PYF Polarized requirement of quality attributes for all malt and adjunct brewing Barley and beer flavor attributes Impact of barley and malting process on beer flavor stability Summary 2

Contents Introduction Barley: Quality integrity and supply assurance - Continuous battles against mycotoxins, gushing, PYF Polarized requirement of quality attributes for all malt and adjunct brewing Barley and beer flavor attributes Impact of barley and malting process on beer flavor stability Summary 3

Locally Grown and Malt DON Reduction - Post-harvest treatments - often impact germ vigor! Chemical Treatment on DON reduction Approaches on DON control: DON 2.5 2 1.5 1 0.5 0 GermDay1 Control Bata-acid Sodium Bisulphide NaOH (ph11.51) - Breeding effort for scab resistant varieties - Crop management practice Treatment - Growing region selections Germ Score 6 5 4 3 2 1 0 GermDay1 Control Germination Score Bata-acid Treatment Sodium Bisulphide Aron et. al. EBC 2017 NaOH (ph11.51) - Mycotoxin monitoring and control in barley selection - Post harvest treatments without negative impacting germination 4

Contents Introduction Barley: Quality integrity and supply assurance - Continuous battles against mycotoxins, gushing, PYF Polarized requirement of quality attributes for all malt and adjunct brewing Barley and beer flavor attributes Impact of barley and malting process on beer flavor stability Summary 5

Proteolysis and Cytolysis during Germination 250.00 FAN 500 450 β-glucan 300 β-glucanase 200.00 400 250 150.00 350 300 200 250 150 100.00 200 150 100 50.00 100 50 50 0.00 D1 D2 D3 D4 Cope D1 Cope D2 Cope D3 Cope D4 0 D1 D2 D3 D4 Cope D1 Cope D2 Cope D3 Cope D4 0 D0 D1 D2 D3 D4 Cope D0 Cope D1 Cope D2 Cope Cope D3 D4 FAN increased rapidly during early stages of germination but β-glucan reduction did not follow the same trend. While the much cytolysis occurred in the first two days for Copeland, acle showed very gradual cytolysis Last day of germination was critical for bringing down its β-glucans to acceptable level. 6

Balance of FAN and β-glucan in malt With barley proteins at >11%, when the β- glucan is controlled at <200, the FAN level is likely >200. Yin et. al. EBC 2017 Opportunity: Alter the ratio of endo-peptidase/exo-peptidase, as well as cell walls? 7

Cell wall polysaccharide continues to be an opportunity area Hydration at the end of steep (40 hrs, 2 immersions) Water distribution takes place at different rate, possibly due to the kernel texture and cell wall thickness Yin et. al.1997 Frequency (Seed total) 30 25 20 15 10 5 0 24 26 28 30 32 34 36 38 40 42 % Moisture in barley 6 hour steep Admiral Low utility NIR Flagship NIR Gairdner NIR Schooner NIR Beta-glucan distribution in the grain endosperm may also be involved in the ability to produce malt with less utility use. 8

Contents Introduction Barley: Quality integrity and supply assurance - Continuous battles against mycotoxins, gushing, PYF Polarized requirement of quality attributes for all malt and adjunct brewing Barley and beer flavor attributes Impact of barley and malting process on beer flavor stability Summary 9

The science of malt flavor - Impact by variety / process ASBC hot steep sensory project Mall and Voigt et. al. EBC 2017 Hayes et al. 2017 10

Dynamics of flavor development in malt roasting As the malt color develops to darker ranges, sweet notes turns into bitter and burnt notes Profile of flavor balance is dependent on the point of cut off in roasting Relative Concentration Color and Wort Volatiles 3-Methylbutanal Furfural Hexanal malty flavor odor of almonds, a components found in vanilla freshly cut grass 0 50 100 150 200 250 300 350 Malt Color EBC Based on Coghe et.al. 2004 11

Malt Amino Acid Matters for Flavor Formation - Examples of volatiles from Maillard reaction Amino acid Glycine Glutamine Valine Cysteine Cystine Methionine Aroma of reaction product with glucose Caramel Chocolate Rye bread Meaty Burnt turkey skin Potato S-containing amino acids produce different flavors than other amino acids Amino acid spectrum in barley varieties and degree of proteolysis in malting therefore affect the flavor profile of the malt http://www.intechopen.com/source/html/40691/media/image2_w.jpg 12

Contents Introduction Barley: Quality integrity and supply assurance - Continuous battles against mycotoxins, gushing, PYF Polarized requirement of quality attributes for all malt and adjunct brewing Barley and beer flavor attributes Impact of barley and malting process on beer flavor stability Summary 13

Changes in flavor profile during beer aging FRESH BEER STALE BEER High Bitterness Fruity/Estery Many precursors for these two mechanisms are from malt Papery/Cardboardy Hop Character Sweetness/Caramel Sensory Intensity Low Sweetness/Caramel Yeasty/Sulfury Astringency Papery/Cardboardy Astringency Fruity/Estery Hop Character Bitterness Yeasty/Sulfury Trend During Aging The balance of the flavor attributes makes the perception of beer 14 at the time of consumption

High heat can inactivate LOX, but can create other complications - Heating in kilning denatures the LOX activity - While kilning intensity is recognized as one of the options to assist in controlling LOX in the finished malt, adverse effect on other key parameters like malt color, hydrolytic enzymes and thermal loads could be resulted in with the shift in malt curing conditions. LOX 140 120 100 80 60 40 20 0 Change in activity at different layers of the kiln bed Bottom Layer Middle Layer Kiln Time (Hours) Upper Layer 0 2 4 6 8 11 13 off kiln Yin, 2013 Malt LOX: Upper 2.2 Middle 1.3 Bottom 0.8 15

Beer amino acid Malt matters FAN reduction Days of Fermentation Yin, 2001 - Amino acid levels vary from 1000mg/L in some main stream light beers to 5000 mg/l in some specialty beers - Strecker amino acid like Alanine and Phenylalanine present in significant level Edwards WBC2016 16

Amino Acid Strecker Degradation of Amino-Acids and Resultant Flavor Compounds Strecker Aldehyde (Examples from literature - Meilgaard, 1975; Ho, 1996) Threshold (PPM) Odor Characteristics Alanine Acetaldehyde CH3CHO 10 Pungent, green, sweet Valine Isobutyraaldehyde (CH3)2CHCHO (1.0) Pungent, green, fruity/banana @ v. low conc. Extremely diffusive Leucine Isoleucine Phenylalanine Methionine Isovaleraldehyde (CH3)2CHCH2CHO 2-Methylbutanal CH3CH2CH(CH3)CHO Phenylacetaldehyde C6H5CH2CHO Methional CH3S.CH2CH2CHO (0.6) Acrid-pungent, fruity/ pleasant @ v. low conc. 1.25 Roasted cocoa or coffee like. Fruity@ v. low conc. (1.6) Powerful, pungent, floral, sweet (0.25) Onion-meat-like, cooked potato Ø Reaction catalysed by diketones / indirect need for O 2 Ø In beer, reaction favoured by high temperatures and high ph (4.3-4.6) Ø May happen in the bottle even at room temperature 17

Effect of Amino Acid on Free Radical Levels FAN levels of malt are correlated with the wort EPR signal strength. Some amino acids gives significantly higher EPR response, which could be a factor for barley variety selection and processing 18

Ratio of Amino Acids in Harrington and Robust Malt 35.00 30.00 Harrington 25.00 20.00 15.00 10.00 5.00 Har HarrHSN HarHSN1 Robust 0.00 Class-III crucial Class-II important ClassIothers Proline Ratio of amino acids not affected significantly by process, e.g. proline % Variation comes from the varieties Yin, 7 th CBS, 2012 19

Cluster Analysis of Varieties based on Wort Amino Acid Contents MB1 MB2 MB3 MB4 Geography and barley type (2R/6R) are possible dominant factors Yin, 7 th CBS, 2012

Statistical Analyses of Amino Acids in Wort Proline Amino Acid STDEV Proline 3.31 Arginine 1.31 Glutamic Acid 0.75 Leucine 0.67 Valine 0.50 Alanine 0.50 Phenylalanine 0.46 Factor1 Leucine Lysine Serine Isoleucine Phenylalanine Glycine Histidine Valine Cystine Methionine Factor2 Tyrosine Tryptophan Threonine Aspartic Acid Alanine Factor3 Glutamic Acid Arginine Pro, Arg, and Glu (% of total AA) are the most variable among the 21 varieties Yin, 7 th CBS, 2012

Correlation of proline and arginine 28 Kendall Manley Alfa B1215 Metcalfe R= - 0.81 26 NA2RM 24 Stein Harrington Stratus Proline Nevada Scarlett Barke 22 B1202 Excel 20 Drummond B1602 Foster NA2RG Stander 18 Robust Esterel 12 14 16 Arginine Ration of Pro negatively affects that of Arg to a large degree Yin, 7 th CBS, 2012

Metabolite variation in barley Possible association with beer Flavor Stability Marker 5-MTA 5-methylthioadenosine (5-MTA) May Be a Good Marker for Flavor Stability - Heuberger et al 2016

Summary All-malt brewing requires moderate FAN with balanced quality while there is an increasing reliance of the global markets on higher protein barley from Canada Low LOX is desirable but with balanced color, DP, and thermal load Barley variety development and breeding: Critical for supply assurance of quality barley free from concerns over food safety and process effectiveness Leverage entire supply chain and scientific advances Needs to understand impact on flavor profile and stability of amino acid composition at the variety level, and innovate accordingly 24

Acknowledgements Rahr Malting and Rahr Corporation Former technical colleagues at Cargill Malt and SABMiller Thank all of YOU! 25