1. Short tour around Hops with HVG & AGRARIA
Carlos Ruiz
Wolnzach, June 2015

2. Content
Hops in Beer and as a result Motto and Vision of HVG
Main Hop Varieties in Germany
Hop Products of HVG and Quality Chain from Hops to Hop Products

3. 3 important groups of substances
Hops in Beer
3 important groups of substances
Bitter substances
Aroma compounds
Polyphenols

4. Quotations from the Hop Book
„At one extreme, hops are simply employed to add bitterness, but at the other, hop varieties are utilized in a number of ways to impart mouthfeel and aroma to beer.“
„Even using the same technology, the sensory results obtained by different research groups will by no means be identical.“
„The authors realized that there are no clear and simple rules pertaining to the process of hopping beer. Depending on the hopping technique, the amount of hops remaining in beer ranges from only few mg of iso-alpha-acids per liter to circa 100 mg per liter of various bitter substances and polyphenols along with more than 100 µg per liter of aroma compounds.“

5. Two commercial Beers (aprox. 20 Bitter Units)
(mg/l)
IAS = Iso- α-Acids
nIAS = non-iso-α-acids bitter substances
AS = Aroma Substances
PP = Polyphenols
Others = Glycosides, Proteins, …

6. Our Motto
„There are thus far no known hop compounds with a negative influence on beer quality if one excludes environmental contaminants like pesticides, nitrates and metals. Consequently it would not be necessary to eleminate any hop compounds with respect to the quality of the beer from a sensory standpoint.“

7. Hops in Beer Hops can…. generate bitterness through iso-α-acids (IAA)
define quality of bitterness through non-iso-α-acid-bitter-substances (nIAA)
create a diversity of hop aromatic impressions through aroma components
create taste: palatefullness, mouthfeel, drinkability and harmony through water-soluble substances like polyphenols, glycosides
improve foam
improve flavour stability

8. Overview of sensoric Effects of Bitter Compounds
Accompanying (NIAA) bitter substances show a pleasant bitterness; β:α is an interesting indicator
Polyphenolic bitter substances (Hard Resins, others) show a very pleasant bitterness
Low cohumulon ratio is positive for quality of bitterness, foam and flavour stability
α-acids are positive for foam and flavour stability
These effects become more evident by dosing of aroma hops in later hop additions

9. Hop Aroma in Beer Estimation of the world beer market
Not desired: more than 60%
Indirectly desired: % (this ratio increases; search for innovative flavour impressions from hops)
Directly desired: less than 10% (this ratio increases; scene of craft brewers)

10. Differentiation of Hop Aroma in Beer
„Kettle hop flavour“: beginning of boil (BB), seldom perceptible „Late hop aroma“: end of boil (EB) or whirpool (WP); goal is a perceptible hopnote („Hopfenblume“) „Dry hop aroma“: Dry-hopping into the cold beer, hop aroma is linked to a specific variety

11. Descriptors of Hop Aroma
There exist different proposals, f.i.
Beer aroma wheel, many examples
Descriptors according properties like flowery, fruity,
citrussy, hoppy, herbal, woody…
Descriptors according comparison like:
Apple, Orange, Grapefruit, Vanilla, Melon, Lemon,
Mandarin, Ananas, Passion Fruit,…
 No uniform understanding of different panels

12. What are Polyphenols (PP)?
Secondary Metabolites like bitter and aroma components
~ 5000 known in the world of plants, many of them have a positive reputation (health benefits) as e.g. antioxidants and radical scavengers…

13. Hop Polyphenols and Beer Taste
Prejudice:
„PP are responsible for a tannic bitterness“
>50 years ago:
Hops stored in air resulted in oxidized and polymerized PP
Longer boiling time (>120 min.) with contact to oxygen
Today:
Hops are stored in cold warehouses
Hops and pellets are packed inert
Boiling time < 60 min without air/oxygen
Hop PP are dosed in „fresh“ form to the beer
 Positive influence on beer flavour

14. Palatefullness

15. Main variable Parameters for Hopping
Hop varieties (n > 100)
Growing conditions
Country, region
Harvest time (colour, max α, max oil?)
Handling of cone hops (temperature, density, oxygen?)
Hop product
Whole hops (inert packaging!)
Pellets / Extract
„Advanced“ Products (Iso, Aroma)
Criteria and quantity of dosage (weight, α, oil, Linalool, PP, others)
Time of addition (BB, MB, EB, WP, Dry Hopping…)

16. Thoughts on Hop Varieties
The later the hop dosage, the less alternatives concerning the selection of possible hop varieties
Think of alternatives or use a blend of 2 or even more varieties. The ratio may vary according to crop results.
number

17. „Make use of hops in its natural form!“
Our Vision
„Make use of hops in its natural form!“

18. Hop Varieties Official groups: aroma & bitter
Defining aroma and bitter varieties
No clear differentiation possible according chemical composition
More oriented on application; bitter hops provide beer bitterness; aroma hops fulfill additionally other purposes
Expectations: bitter hops > 10% α, strong aroma; aroma hops < 10% α, mild aroma, high polyphenol content

19. Additional (inofficial) groups
Dual-purpose hops (f.i. Chinook, Centennial)
Noble (aroma) hops = land races (f.i. Tettnang, Spalt, Hersbruck, Hallertau Mittelfrueh, Saaz)
Hops with special flavor = special flavor hops = flavor hops = hops with unique flavor  mainly used for dry hopping

20. Characterisation of hop varieties
Agronomic characteristics: yield, resitance to deseases…
Chemical compounds (examples): α-acids, β:α, cohumulone-ratio, polyphenols, polyphenols:α, total oil, total oil:α, linalool, linalool:α

21. German Noble Aroma Hops
Dimension
Spalt
Tettnang
Hall. Mfr.
Hersbruck
Average
α-acids
%w/w
4.1
3.1
3.9
β:α
1.3
2.4
1.6
Cohumulone
%rel. 24 21 20 22
Polyphenols
5.3
4.6
4.4
4.9
Polyphenols:α
1.1
1.4
Total oil
ml/100g
0.60
0.85
0.75
0.70
Total oil:α
ml/g
0.15
0.21
0.24
0.19
Linalool
mg/100g 4 6 5
4.8
Linalool:α
mg/g
1.0
1.5

22. German Aroma Hops bred in Huell
Dim.
Perle
Tradition
Select
Saphir
Opal
Smaragd
Averg.
α-acids
%w/w
7.4
6.2
5.1
4.1
7.9
5.9
6.1
β:α
0.7
0.8
1.0
1.9
0.9
Cohumulone
%rel. 30 26 23 15 21
Polyphenols
4.3
4.9
4.5
3.7
Polyphenols:α
0.6
1.1
0.5
Total oil
ml/100g
1.30
0.70
1.10
0.95
0.90
0.94
Total oil:α
ml/g
0.18
0.11
0.14
0.27
0.12
0.16
Linalool
mg/100g 4 7 8 10 11
8.3
Linalool:α
mg/g
1.6
2.4
1.4
1.7
1.3

23. German Bitter Hops Dimension North. Brew. Magnum Taurus Herkules
Average
α-acids
%w/w
9.2
13.9
15.9
13.7
β:α
0.6
0.5
0.3
0.43
Cohumulone
%rel. 27 23 36 28
Polyphenols
3.9
2.6
3.1
3.5
3.3
Polyphenols:α
0.4
0.2
0.25
Total oil
ml/100g
1.5
2.4
2.0
1.8
1.9
Total oil:α
ml/g
0.16
0.17
0.13
0.11
0.14
Linalool
mg/100g 4 8 19 10
Linalool:α
mg/g
1.2
0.7

24. Averages Dimension Noble Aroma Aroma Bitter α-acids %w/w 3.9 6.1 13.7
β:α
1.6
1.0
0.43
Cohumulone
%rel. 22 21 28
Polyphenols
4.9
4.3
3.3
Polyphenols:α
1.3
0.8
0.25
Total oil
ml/100g
0.70
0.94
1.9
Total oil:α
ml/g
0.19
0.16
0.14
Linalool
mg/100g
4.8
8.3 10
Linalool:α
mg/g
0.7

25. German Special Flavor Hops
Dimension
H. Cascade
Blanc
Melon
Mandarina
Polaris
α-acids
%w/w
5.9
9.7
7.2
8.4
19.7
β:α
1.0
0.5
1.2
0.6
0.3
Cohumulone
%rel. 31 24 29 33
Polyphenols
3.2
5.7
4.5
4.1
3.5
Polyphenols:α
0.2
Total oil
ml/100g
1.3
1.6
3.9
Total oil:α
ml/g
0.20
0.13
0.22
0.14
Linalool
mg/100g 6 5 7 9
Linalool:α
mg/g
1.1
0.7
0.8

26. Selected Aroma Substances mg/100g
Hall. Mfr.
Saphir
H. Cascade
Melon
Mandarina
Blanc
Polaris
Myrcene
173
428
720
771
833
914
2,248
β-Caryophyllene 76 48 25 46 52
278
Humulene
273
113
134
143
145
739
α- + β-Selinene 10 14
193
218 27
Linalool 6 9 5 7
Geraniol 1 8 2 4
Geranylacetate 15 17
Sum of 9 Esters 11 13 36
106 87 89
359

27. Hop Dosing Regime (yield in %rel.)
α-acids
Polyphenols
Esters/Alc.
Terpenes
Begin of boil
40-50
50-60
Middle of boil
15-25 50 5
End of boil 10
30-50
<2
Whirpool
5-10
40-60
Dry hopping
up to 50
up to 100
up to 5
BB Bitter hops  Bitterness
MB Aroma hops  Palatefullness
EB/WP Aroma hops  Palatefullness + flavor
Dry Aroma/flavor hops  individual flavor

29. Conventional Hop Products
Problems with whole hops
Logistic
Heterogenity
Stability
Automatic dosing
Yields
Wort clarification
Conventional hop products should overcome the disadvantages of whole hops without chemical changes of substances by gentle processes.

30. Whole Hops In bales: oxygen is present!
In gas-tight foil bags: inert like pellets
HVG produces Vakupacks= whole hops pressed (500kg/m3): packed in foils under vacuum; lupulin glands are crushed (better extraction of hop oil)

31. Pellets
Regular pellets= Type 90; yield approx kg pellets from 100 kg hops; identical with hops
Enriched pellets= type 45; yield approx kg pellets from 100 kg hops; alpha and oil enriched up to a double of hops

32. Flow Chart of normal Hop Pellets

33. Background of enriched Pellets
Seperation of lupulin glands from leafs (waste)
Grinding and seaving are only possible with hard lupulin glands
The liquid phase of resin and oil in the lupulin must be hard, which needs temperatures below -20°C

34. Lupulin Glands

35. Flow Chart of enriched Pellets

36. Comparison of normal and enriched Pellets (values in %rel
Comparison of normal and enriched Pellets (values in %rel. to amounts of whole hops)

37. Sensitive Steps during the Pellet Production
Product Temperature Exposure Time
Kilning < 60 °C < 30 min
Grinding < 20 °C few seconds
Sieving for Type < -30 °C
Mixing powder < 20 °C < 120 min
Pelletiziation < 55 °C few seconds
Pellet cooling < 18 °C < 20 min

38. Packing in Foils Oxygen-diffusion of the foil material:
< 0.5 ml/m² * 24h * 1bar
More than 95% of all packed foils
less than 1% v/v Oxygen

39. Carbon Dioxide Extraction

40. Flow Chart of a supercritical CO2-Extraction

41. Hop Oil Production

43. The Quality Chain from Hops to Hop Products
Definition of “Quality Chain“:
All processes from hops untill dosage in the brew house are parts of the quality chain
Goal of an optimal quality chain is the best possible identity of all components between the harvest at hop and ist dosage in form of a hop product

44. Can Hops be a Risk for Health?
 Components
 Deterioration
 Contamination with
- Plant protection substances
- Heavy metals
- Mycotoxines
- Microbiology?

45. Definition of "Quality"
Definition is being done normally according to Variety and Growing area
Definition in this case:
"Quality defines the degree of deterioration of the hop components from the harvest until the dosing into the wort."

46. Quality = Freshness
Analytical indices such as alpha degradation or Hop Storage Index (HSI) describe only partial aspects.
All important hop components suffer through deterioration
 Bitter substances
 Aroma substances
 Polyphenols

47. Hop Quality according to the Deterioration vs. freshly harvested Hops
Category of Loss of Alpha-acids Hop Storage
Freshness / Ageing in % rel Index
Fresh to 10 < 0.32
Slightly deteriorated to to 0.40
Deteriorated to to 0.50
Strongly deteriorated to to 0.60
Overaged > > 0.61

48. Steps of a "Quality Chain" with conventional Hop Products
 Hop harvest with picking, drying, conditioning, baling
 Storage in form of cone hops
 Processing to hop products
 Storage of hop products
 Transport to the brewery
 Storage and dosing in the brewery

49. Drying of Hops What is the "right drying temperature"?
Common understanding today: Tmax = 63 °C
Enzymatic reactions of polyphenols are unclear
 new findings may result in new rules

50. Goal is the homogenisation of the moisture
Conditioning of Hops
Goal is the homogenisation of the moisture
within the cones.
 hours conditioning with circulating air
 Afterwards blending of outside and inside air
according to desired water content
Air temperature of approx. 18 °C

51. Correlation of Humidity in the Air and the Moisture of Hops
Desired Moisture Air Humidity
Weight - % % relative
12 65
10 60
9 55
8 50

52. Packing of Hops Goal: Optimal logistics with minimal damaging
of the lupulin membrane
 Better storage stability through limited
oxidation protection of the lupulin membrane
 Requirement for lupulin enriched pellets
(Type 45) are intact lupulin glands

53. Lupulin Glands from Bales
139 kg/m3
185 kg/m3

54. 12 varieties were stored in 3 types of storage:
Hop Storage Trials
12 varieties were stored in 3 types of storage:
- Moderate storage ( 5 to 30 °C)
- Good storage ( 5 to 20 °C)
- Cold storage ( 1 to 5 °C)

55. Summary of Storage Tests
Average changes after three month in % relative
Moderate Good Cold
Storage Storage Storage
Decrease of alpha
Increase of HSI
EBC 7.7
ASBC

56. Consequences  Cold storage of hops soonest possible after the crop
 Optimal systems for an economical storage

57. Improvement of Hop Products
 Logistic
 Homogeneity
 Stability
 Dosing in the brew house
Hop production means to overcome the disadvantages
of cone hops without damaging components.

58. Sensitive Steps during the Pellet Production
Product Temperature Exposure Time
Kilning < 60 °C < 30 min
Grinding < 20 °C few seconds
Sieving for Type < -30 °C
Mixing powder < 20 °C < 120 min
Pelletiziation < 55 °C few seconds
Pellet cooling < 18 °C < 20 min

59. Physical Characteristics of Pellet Foils
Quality criterion Method Example for Limits
Diffusion of oxygen DIN <0.5 ml/m2/24 h/1 bar
Stability of weld seam DIN > 20 Newton
Penetration resistance DIN > 300 Newton
O2 in foils several < 0.5 vol-% O2

60. Physical Characteristics of Cartons
Quality criterion Method Example for Limits
Stackability test EN-DIN > 17 kN/m
Penetration test DIN > 18 Joule

61. Proposed Storage Temperature for
Hops and Hop Products
Intended storage time
1 year years years
Whole hops 0 °C °C not practicable
Pellets to 15 °C °C °C
Extracts < 20 °C °C °C

62. Temperature in a Container "winter normal"•

63. Temperature in a Container "on deck"

64. Temperature in a Container "harbour"

65. Temperature in a Container "disastrous"

66. Consequences during Pellet Transport
 With an intact foil only inert reactions occur;
Alpha-losses % relative; unpleasant aroma substances will be formed
 Formation of gas
 pressure increases
 foil gets a hole
Gas escapes and air penetrates
 Oxidation up to total loss
 Timing of shipment (winter months) or preferably the use of reefer containers

67. Damaging potential of alpha-acids (% rel.)
CONCLUSIONS
Damaging potential of alpha-acids (% rel.)
Pellets Extracts
conditions conditions
Good Moderate Good Moderate
Kilning + conditioning to to
Storage of whole Hops to to
Production* to to
Storage for 1 year to to
Overseas shipment
Total to to
* Alpha-losses in form of yield not taken into consideration

68. Think of strategic Stocks
You as a brewer have developed a beer with a special recipe and defined hops. In a short crop, these hops are very expensive or not even available. Properly packed hops or pellets (O2-free) stored at approx. 0°C keep quality for several years. Be more independent of bad (and expensive) crops, especially in the case of aroma hops with special character. A product, some years old, produced from a good crop is better than a product of a current bad crop. A simple rule: good crops in quantity are normally combined with high quality and often with low spot prices for some varieties.

69. Summary (1)  "Quality" is the degree of freshness
independent of the growing area and the hop variety.
 A degradation of bitter acids, aroma components and
polyphenols from the time of harvest to the point of
hop addition to the kettle is defined as ageing.
 There are analytical methods (ageing indicators
like HSI), but further research is necessary.

70. Summary (2)
"Quality chain" comprises all processes from
harvest to the dosage into the wort.
Farmer, Processor and Brewer are partners
in the quality chain. They are responsible to
prevent damages of hop components.

71. Thank you for your attention!