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

Transcription

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

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

3 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

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

5 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

6 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 (%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 Water 8 12 Lupulin glands 6

7 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

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

9 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 A A 275 ) β acids, % = d (5557A A A 275 ) 9

10 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

11 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

12 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

13 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

14 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

15 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 Fingerprinting using 30 marker compounds Differentiation of hop varieties 15

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18 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

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

20 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

21 EKG1 EKG2 EKG3 EKG4 EKG5 EKG6 EKG7 EKG8 EKG9 21

22 Composition of hop aroma at time of picking 22

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

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

25 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

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

27 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

28 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 fresh hops Cascade () dry leaf % baled % Columbus () dry leaf % baled % pellets pellets Goldings (B) fresh hops dry leaf % pellets % Magnum (B) fresh hops dry leaf % pellets % 28

29 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

30 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

31 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

32 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

33 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

34 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

35 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

36 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

37 CASE STUDIES GROWTH LOCATION Cascade: Belgium (B) vs α-acids (%) β-acids (%) HSI Hop oil content (ml/100 g) Cascade B Cascade B Cascade Cascade

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

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

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

41 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 Tettnanger B Tettnanger D Tettnanger D Tettnanger_2011_ Tettnanger_2012_

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

43 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

44 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

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

46 CASE STUDIES QUALITY CONTROL AMARILLO crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) AMA (ID) AMA (ID) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (ID) AMA (ID) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) rejected 46

47 CASE STUDIES QUALITY CONTROL CASCADE crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) CAS Belgium CAS CAS CAS Belgium CAS CAS Belgium CAS CAS CAS Germany CAS Australia

48 CASE STUDIES QUALITY CONTROL CITRA crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) CIT CIT CIT CIT CIT CIT CIT CIT CIT CIT lupulin powder CIT

49 CASE STUDIES QUALITY CONTROL MOSAIC crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) MOS MOS MOS MOS MOS MOS MOS MOS MOS MOS MOS MOS

50 CASE STUDIES QUALITY CONTROL SIMCOE crop origin α-acids (%) β-acids (%) HSI hop oil content (ml/100 g) SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM

51 51 Hoparoma_terroir (<All Characters>) 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 AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA CAS CAS CAS CAS CIT CIT CIT CIT CIT CIT CIT CIT CIT CIT SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM MOS MOS MOS MOS MOS MOS MOS MOS AMA AMA AMA AMA CAS CAS CAS CAS CAS (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

52 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 (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) AMA (WA) Cascade CAS Cascade CAS Cascade CAS Cascade CAS CIT CIT CIT CIT CIT CIT CIT CIT CIT CIT SIM SIM

53 53 Hoparoma_terroir (<All Characters>) 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 AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA AMA CAS CAS CAS CAS CIT CIT CIT CIT CIT CIT CIT CIT CIT CIT SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM SIM MOS MOS MOS MOS MOS MOS MOS MOS AMA AMA AMA AMA CAS CAS CAS CAS CAS (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!

54 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

55 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 55

56 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

57 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

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