THE BREWING VALUE OF HOPS HOP & BREW SCHOOL A UG 29 S EPT 1, 2017, Y AKIMA

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Summary Take home messages 2

INTRODUCTION Unreliable hop quality variations in quality of dry hopped beers Hop research at De Proefbrouwerij Single Hop Technology project (IWT project, 2011-) Follow up of 20 hop varieties (, B, CZ) for 3 successive harvest years Evaluation of derived single-hop beers Single Hop Science project (Proefbrouwerij initiative, since ) Feedback to hop growers and suppliers Introduction of hop quality parameters Quality control and authentication of raw materials Increase of reproducibility and quality level of derived (single-hop) beers 3

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Summary Take home messages 4

BREWING VALUE OF HOPS What information do brewers have on the hops they are using? What information do growers/suppliers have on the impact of their hops (varieties, processing, ) on the quality of derived beers? 5

BREWING VALUE OF HOPS Chemical composition of hops (dried hop cones) Components Amount % (w/w) α-acids 2 19 β-acids 2 10 Essential oil 05 30 (%v/w) Polyphenols 3 6 Monosaccharides 2 Amino acids 01 Proteines 15 Lipids and fatty acids 1 5 Pectins 2 Ash salts 10 Cellulose - lignins 40 50 Water 8 12 Lupulin glands 6

BREWING VALUE OF HOPS Brewing value of hops is determined by 3 types of secondary metabolites: hop acids (particularly the α-acids) hop essential oil components (aroma) polyphenols 7

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Summary Take home messages 8

BREWING VALUE OF HOPS ANALYSIS HOP ACIDS: α-acids (= humulones) 2 19 % (w/w) α-acids iso-α-acids: beer bitterness β-acids (= lupulones) 2 10 % (w/w) Spectrophotometric determination using ASBC method Hops-6A α acids, % = d ( 5156A 355 + 7379A 325 1907A 275 ) β acids, % = d (5557A 355 4759A 325 + 510A 275 ) 9

BREWING VALUE OF HOPS ANALYSIS HOP ACIDS: differences between analytical methods LCV ( Lead Conductance Value ) - EBC 75 Spectrophotometric methods - ASBC Hops-6A HPLC ( High-Performance Liquid Chromatography ) - EBC 77, ASBC Hops-14 Hopsteiner Newsletter 02/ Technical support 10

BREWING VALUE OF HOPS ANALYSIS HSI (= Hop Storage Index): QUALITY PARAMETER HSI can be used to evaluate the freshness of hops; HSI increases with time, temperature and hop damage (picking/processing/storage) Assessment of hop quality using HSI-values (De Proefbrouwerij): HSI < 030: good quality 030 < HSI < 040: acceptable quality, but the lower HSI - the better 040 < HSI < 050: debatable quality, preferably reject (esp aroma varieties) HSI > 050: poor quality reject Spectrophotometric determination using ASBC method Hops-12 HSI = A 275 A 325 OXIDATION 11

BREWING VALUE OF HOPS ANALYSIS HOP ESSENTIAL OIL: AMOUNT of hop essential oil 05 3 ml / 100 grams of dried hop cones Determination by steam distillation (EBC 710) 12

BREWING VALUE OF HOPS ANALYSIS HOP ESSENTIAL OIL: AMOUNT of hop essential oil COMPOSITION of hop essential oil Complex mixture of volatiles; >400 compounds identified Hop aroma profiling via HS-SPME-GC-MS analysis 13

BREWING VALUE OF HOPS ANALYSIS HOP ESSENTIAL OIL: hop aroma profiling via HS-SPME-GC-MS analysis EXTRACTION (HS-SPME) DETECTION (MS) SEPARATION (GC) 14

BREWING VALUE OF HOPS ANALYSIS SUMMARY Hop acids (α-acids and β-acids) Straightforward and inexpensive analysis (spectrophotometric determination) Amounts depend mainly on variety, crop year, processing / packaging / storage QUALITY PARAMETER HSI depends mainly on processing / packaging / storage Hop essential oil AMOUNT of hop essential oil Straightforward and inexpensive analysis Depends mainly on hop variety, crop year, processing / packaging / storage COMPOSITION of hop essential oil: complicated and quite expensive analysis good indication of origin (growth location/ terroir ) 18

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Hop picking Summary Take home messages 19

CASE STUDIES HOP PICKING Follow up of hop ripening 9 hop growers (Belgium) 4 hop varieties (Goldings, Cascade, Challenger, Magnum) 2 samplings per week (1 plant) 20

EKG1 EKG2 EKG3 EKG4 EKG5 EKG6 EKG7 EKG8 EKG9 21

Composition of hop aroma at time of picking 22

CASE STUDIES HOP PICKING Follow up of hop ripening Comparison of dried (and pressed) hop cones 23

CASE STUDIES HOP PICKING Follow up of hop ripening Comparison of dried (and pressed) hop cones 24

CASE STUDIES HOP PICKING SUMMARY Similar evolution of hop acids and amount of hop essential oil on all fields Ripening is variety-dependent: aroma hops < dual purpose hops < bitter hops Correct choice of harvest time by growers (= at technological ripeness) Large variations in amounts of hop oil in dried (and pressed) hop cones Influence of weather conditions (hail)? Influence of processing: quality losses during drying and packaging into bales? Clustering of hop varieties based on hop aroma profiles BELGIAN TERROIR 25

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Hop picking Hop processing Summary Take home messages 26

CASE STUDIES HOP PROCESSING Drying process Evaluation of different time-temperature regimes during drying of hop cones: Fresh hops Cones dried at 56 C for 5 hours Cones dried at 56 C for 10 hours Cones dried at 67 C for 5 hours (eg Hallertau Mittelfrüh) 27

CASE STUDIES HOP PROCESSING Drying process Pressing into bales Evaluation of hop quality throughout processing (impact pressing into bales): AROMA HOP α-acids (%) β-acids (%) HSI Hop oil content (ml / 100g DM) BITTER HOP α-acids (%) β-acids (%) HSI Hop oil content (ml / 100g DM) fresh hops 82 83 027 219 fresh hops 179 46 033 538 Cascade () dry leaf 72 77-25% 023 217 baled 65 68 031 181-45% Columbus () dry leaf 177 49-27% 034 415 baled 050 281-57% pellets 61 64 033 120 pellets 131 35 048 234 Goldings (B) fresh hops 107 46 028 157 dry leaf 97 42-11% 030 127 pellets 95 41 028 108-31% Magnum (B) fresh hops 220 86 028 421 dry leaf 195 73-13% 026 390 pellets 192 70 027 324-23% 28

CASE STUDIES HOP PROCESSING Drying process Pressing into bales Evaluation of hop quality throughout processing (with pressing into bales): BEFORE AFTER Damage of lupulin glands under high pressure 29

CASE STUDIES HOP PROCESSING Drying process Pressing into bales Pelleting Use of different heat loads during production of pellets: Dried hop cones normal pellets bad pellets (eg Magnum) 30

CASE STUDIES HOP PROCESSING SUMMARY Process control is essential for maintenance of hop quality throughout processing: Monitoring of time-temperature regime during drying of hop cones Limiting pressure during pressing into bales Fine tuning of settings during pelletizing (low heat load) 31

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Hop picking Hop processing Hop storage Summary Take home messages 32

CASE STUDIES HOP STORAGE Storage stability study of hops Evaluation of pellets stored during 3 / 6 / 12 / 24 months at different storage conditions: Temperature -18 C (freezer) 1 C (fridge) 20 C (room temperature) Packaging (mylar bags) vacuum sealed air (unsealed package) (eg ) 33

CASE STUDIES HOP STORAGE after 3 months REF aroma profile after 6 months after 12 months after 24 months -18 C vacuum -18 C air 1 C vacuum 1 C air 20 C vacuum 20 C air 34

CASE STUDIES HOP STORAGE SUMMARY Appropriate packaging and storage conditions are necessary to maintain hop quality: Exclusion of air (oxygen) during packaging and storage of hops Long-term storage at -18 C (freezer) is recommended 35

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Hop picking Hop processing Hop storage Growth location Summary Take home messages 36

CASE STUDIES GROWTH LOCATION Cascade: Belgium (B) vs α-acids (%) β-acids (%) HSI Hop oil content (ml/100 g) Cascade B 48 57 034 070 Cascade B 41 53 032 055 Cascade 83 66 029 130 Cascade 56 67 026 095 37

CASE STUDIES GROWTH LOCATION Cascade: Belgium (B) vs 38

CASE STUDIES GROWTH LOCATION Cascade: Belgium (B) vs 39

CASE STUDIES GROWTH LOCATION Cascade: Belgium (B) vs BEER (hoppy aroma) HOPS (hop aroma) 40

CASE STUDIES GROWTH LOCATION Cascade: Belgium (B) vs Tettnanger: Belgium (B) vs Germany (D) vs α-acids (%) β-acids (%) HSI Hop oil content (ml/100 g) Tettnanger B 30 44 032 045 Tettnanger B 34 53 027 045 Tettnanger D 24 40 036 040 Tettnanger D 40 57 029 055 Tettnanger_2011_ 44 26 033 090 Tettnanger_2012_ 37 25 034 060 41

CASE STUDIES GROWTH LOCATION Cascade: Belgium (B) vs Tettnanger: Belgium (B) vs Germany (D) vs + preliminary results DNA fingerprinting different genotypes B = D 42

CASE STUDIES GROWTH LOCATION SUMMARY Hop aroma profiles vary by growth location/ terroir (and to a lesser extent by crop year) Impact of terroir: Belgian Cascade and Tettnanger clearly distinguished from varieties Belgian Tettnanger similar to German Tettnanger European terroir? Need for extra quality parameters and information! Currently: per batch hop variety and amount of α-acids Future: per batch hop variety, α-acids, HSI, hop oil content and growth location 43

Introduction Hop research at De Proefbrouwerij The brewing value of hops Analysis Case studies Hop picking Hop processing Hop storage Growth location Quality control of raw materials Summary Take home messages 44

CASE STUDIES QUALITY CONTROL Assessment of hop quality in brewing practice eg, Cascade,, Mosaic, (several suppliers) 45

CASE STUDIES QUALITY CONTROL AMARILLO crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) AMA-14-01 (ID) 66 47 035 125 AMA-14-02 (ID) 71 51 035 130 AMA-14-03 (WA) 72 56 036 140 AMA-14-04 (WA) 78 59 033 180 AMA-14-05 (WA) 68 56 036 130 AMA-14-06 (WA) 83 61 031 195 AMA-14-07 (WA) 76 57 036 155 AMA-14-08 (WA) 88 61 031 175 AMA-14-09 (WA) 77 58 036 150 AMA-15-01 (WA) 80 54 029 140 AMA-15-02 (WA) 75 57 032 150 AMA-15-03 (WA) 75 57 031 150 AMA-15-04 (ID) 80 62 035 105 AMA-15-05 (ID) 71 53 033 100 AMA-16-01 2016 (WA) 60 47 044 120 AMA-16-02 (WA) 67 55 031 165 AMA-16-03 (WA) 71 55 032 155 AMA-16-04 (WA) 65 54 033 150 AMA-16-05 (WA) 65 53 038 125 AMA-16-06 2016 (WA) 81 61 026 150 AMA-16-07 2016 (WA) 81 64 028 160 AMA-16-08 2016 (WA) 77 61 027 145 rejected 46

CASE STUDIES QUALITY CONTROL CASCADE crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) CAS-13-01 Belgium 53 54 031 070 CAS-14-01 80 65 028 140 CAS-14-02 82 66 027 165 CAS-14-03 Belgium 48 55 034 070 CAS-15-01 56 67 026 095 CAS-15-02 Belgium 41 53 032 055 CAS-15-03 2015 61 70 026 140 CAS-16-02 2016 48 66 026 080 CAS-17-01 2016 Germany 59 60 029 080 CAS-17-02 2016 Australia 61 52 035 100 47

CASE STUDIES QUALITY CONTROL CITRA crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) CIT-13-01 132 29 031 210 CIT-14-01 120 31 037 210 CIT-14-02 115 27 031 175 CIT-14-03 123 36 037 195 CIT-14-04 125 33 032 195 CIT-15-01 100 41 030 165 CIT-16-01 2015 113 28 033 185 CIT-16-02 2015 119 29 034 205 CIT-16-03 2016 118 31 031 140 CIT-17-01 2015 204 45 030 415 lupulin powder CIT-17-02 2016 107 28 031 135 48

CASE STUDIES QUALITY CONTROL MOSAIC crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) MOS-13-01 122 29 031 135 MOS-14-01 73 22 039 130 MOS-15-01 104 32 033 120 MOS-15-02 106 29 039 120 MOS-15-03 106 30 034 115 MOS-16-01 2015 101 28 032 080 MOS-16-02 2015 118 31 032 140 MOS-16-03 2015 117 31 032 145 MOS-16-04 2015 114 31 035 125 MOS-16-05 2016 110 29 032 150 MOS-16-06 2015 108 29 033 130 MOS-17-01 2016 102 28 031 130 49

CASE STUDIES QUALITY CONTROL SIMCOE crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) SIM-13-01 2012 96 28 045 125 SIM-14-01 122 34 031 180 SIM-14-02 122 35 030 190 SIM-14-03 132 37 030 170 SIM-14-04 99 35 030 125 SIM-15-01 101 34 032 165 SIM-15-02 116 33 031 165 SIM-15-03 119 33 031 140 SIM-15-04 117 32 031 210 SIM-15-05 2015 120 40 028 195 SIM-16-01 2015 122 41 028 180 SIM-16-02 2015 111 31 036 155 SIM-16-03 2015 114 31 035 165 SIM-17-01 2016 104 26 032 130 50

51 Hoparoma_terroir (<All Characters>) 100 90 80 70 60 Hoparoma_30markers ß-pinene ß-myrcene 3-methylbutyl 2-methylpropanoate 2-methylbutyl 2-methylpropanoate ß-phellandrene limonene cis-ß-ocimene methyl 6-methylheptanoate terpinolene linalool perillen 2-methylbutyl 2-methylbutanoate 2-methylbutyl 3-methylbutanoate methyl octanoate citral nerol geraniol 2-undecanone methyl 4-decenoate methyl geranate ß-caryophyllene a-bergamotene a-humulene ß-farnesene ß-selinene a-selinene caryophyllene oxide humulene epoxide I humulene epoxide II humulene epoxide III Cascade Cascade Cascade Cascade Mosaic Mosaic Mosaic Mosaic Mosaic Mosaic Mosaic Mosaic Cascade Cascade Cascade Cascade Cascade AMA-14-08 AMA-14-06 AMA-14-04 AMA-16-07 AMA-16-06 AMA-16-02 AMA-16-04 AMA-16-05 AMA-16-03 AMA-14-03 AMA-14-05 AMA-14-07 AMA-14-09 AMA-15-01 AMA-15-03 AMA-15-02 AMA-16-01 AMA-16-08 CAS-14-02 CAS-14-01 CAS-15-01 CAS-16-02 CIT-14-03 CIT-14-04 CIT-14-02 CIT-13-01 CIT-14-01 CIT-15-01 CIT-16-03 CIT-16-02 CIT-16-01 CIT-17-01 SIM-15-01 SIM-14-04 SIM-14-03 SIM-17-01 SIM-13-01 SIM-16-01 SIM-15-05 SIM-14-01 SIM-15-04 SIM-15-03 SIM-15-02 SIM-16-03 SIM-16-02 SIM-14-02 MOS-13-01 MOS-15-02 MOS-14-01 MOS-15-03 MOS-15-01 MOS-16-01 MOS-16-03 MOS-16-02 AMA-14-02 AMA-15-04 AMA-15-05 AMA-14-01 CAS-17-02 CAS-17-01 CAS-14-03 CAS-13-01 CAS-15-02 2016 2016 2016 2016 2016 2016 2015 2015 2015 2016 2012 2015 2015 2015 2015 2015 2015 2015 2016 2016 (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (ID) (ID) (ID) (ID) Australia Germany Belgium Belgium Belgium

60 70 80 90 100 ß-pinene ß-myrcene 3-methylbutyl 2-methylpropanoate 2-methylbutyl 2-methylpropanoate ß-phellandrene limonene cis-ß-ocimene methyl 6-methylheptanoate terpinolene linalool perillen 2-methylbutyl 2-methylbutanoate 2-methylbutyl 3-methylbutanoate methyl octanoate citral nerol geraniol 2-undecanone methyl 4-decenoate methyl geranate ß-caryophyllene a-bergamotene a-humulene ß-farnesene ß-selinene a-selinene caryophyllene oxide humulene epoxide I humulene epoxide II humulene epoxide III Hoparoma_terroir (<All Characters>) Hoparoma_30markers AMA-14-08 (WA) AMA-14-06 (WA) AMA-14-04 (WA) AMA-16-07 2016 (WA) AMA-16-06 2016 (WA) AMA-16-02 (WA) AMA-16-04 (WA) AMA-16-05 (WA) AMA-16-03 (WA) AMA-14-03 (WA) AMA-14-05 (WA) AMA-14-07 (WA) AMA-14-09 (WA) AMA-15-01 (WA) AMA-15-03 (WA) AMA-15-02 (WA) AMA-16-01 2016 (WA) AMA-16-08 2016 (WA) Cascade CAS-14-02 Cascade CAS-14-01 Cascade CAS-15-01 Cascade CAS-16-02 2016 CIT-14-03 CIT-14-04 CIT-14-02 CIT-13-01 CIT-14-01 CIT-15-01 CIT-16-03 2016 CIT-16-02 2015 CIT-16-01 2015 CIT-17-01 2015 SIM-15-01 SIM-14-04 52

53 Hoparoma_terroir (<All Characters>) 100 90 80 70 60 Hoparoma_30markers ß-pinene ß-myrcene 3-methylbutyl 2-methylpropanoate 2-methylbutyl 2-methylpropanoate ß-phellandrene limonene cis-ß-ocimene methyl 6-methylheptanoate terpinolene linalool perillen 2-methylbutyl 2-methylbutanoate 2-methylbutyl 3-methylbutanoate methyl octanoate citral nerol geraniol 2-undecanone methyl 4-decenoate methyl geranate ß-caryophyllene a-bergamotene a-humulene ß-farnesene ß-selinene a-selinene caryophyllene oxide humulene epoxide I humulene epoxide II humulene epoxide III Cascade Cascade Cascade Cascade Mosaic Mosaic Mosaic Mosaic Mosaic Mosaic Mosaic Mosaic Cascade Cascade Cascade Cascade Cascade AMA-14-08 AMA-14-06 AMA-14-04 AMA-16-07 AMA-16-06 AMA-16-02 AMA-16-04 AMA-16-05 AMA-16-03 AMA-14-03 AMA-14-05 AMA-14-07 AMA-14-09 AMA-15-01 AMA-15-03 AMA-15-02 AMA-16-01 AMA-16-08 CAS-14-02 CAS-14-01 CAS-15-01 CAS-16-02 CIT-14-03 CIT-14-04 CIT-14-02 CIT-13-01 CIT-14-01 CIT-15-01 CIT-16-03 CIT-16-02 CIT-16-01 CIT-17-01 SIM-15-01 SIM-14-04 SIM-14-03 SIM-17-01 SIM-13-01 SIM-16-01 SIM-15-05 SIM-14-01 SIM-15-04 SIM-15-03 SIM-15-02 SIM-16-03 SIM-16-02 SIM-14-02 MOS-13-01 MOS-15-02 MOS-14-01 MOS-15-03 MOS-15-01 MOS-16-01 MOS-16-03 MOS-16-02 AMA-14-02 AMA-15-04 AMA-15-05 AMA-14-01 CAS-17-02 CAS-17-01 CAS-14-03 CAS-13-01 CAS-15-02 2016 2016 2016 2016 2016 2016 2015 2015 2015 2016 2012 2015 2015 2015 2015 2015 2015 2015 2016 2016 (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (WA) (ID) (ID) (ID) (ID) Australia Germany Belgium Belgium Belgium Impact of growth location / terroir on hop aroma profiles!

CASE STUDIES QUALITY CONTROL SUMMARY Large batch-to-batch variations in hop oil contents (and amounts of hop acids) ( Calculation of dry hop amounts in function of hop oil contents) Hop aroma profiles vary by growth location/ terroir (and to a lesser extent by crop year) Need for extra quality parameters and information! Currently: per batch hop variety and amount of α-acids Future: per batch hop variety, α-acids, HSI, hop oil content and growth location 54

SUMMARY TAKE HOME MESSAGES Amounts of hop acids depend mainly on variety and crop year HSI is a reliable quality parameter keep the HSI-value as low as possible! Monitoring of temperature and time during drying process Limiting of pressure on hop cones during pressing into bales Control of settings during pelletizing Exclusion of oxygen during packaging of hops (Long-term) storage at freezing temperatures is recommended Hop essential oil Amount: depends mainly on variety and crop year Composition: terroir has a larger influence over yearly variations 56

SUMMARY TAKE HOME MESSAGES Current situation: Hop quality control using following parameters: Amount of α-acids HSI Hop oil content Hop oil composition (hop aroma profiling) Future perspectives: DNA fingerprinting (genotyping) for identification of hop varieties for evaluation of the purity within one batch 57

THANK YOU FOR YOUR ATTENTION HOP & BREW SCHOOL A UG 29 S EPT 1, 2017, Y AKIMA