Ray Marriott 22nd March 2018

Dry Hopping - a new look at techniques,

utilisation and economics

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 1

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 2

Dry hopping is a pain!

Hops and pellets (to a lesser degree) are bulky and unstable and ideally need

cold storage

Only a small proportion of the brewing value is used in dry hopping

Efficient dry-hopping requires capital investment and equipment can be

occupied for days

Beer losses are substantial at high hopping rates

As highly hopped beers gain in popularity translation to large scale production

introduces significant handling issue

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 3

Objectives

Identify key parameters that impact the transfer of hop aroma molecules

to beer

Understand the mechanism of hop derived molecule distribution in the

final beer

Develop a model to predict hop aroma profile in the final beer

Develop alternative strategies for more efficient and economic dry

hopping

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 4

Fix known optimum parameters

Select variables

Dry hopping trials

Beer analysis

Hop analysis

Physicochemical data of metabolites

Process modeling

Product development

Project plan

Review existing optimisation data

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section

Dry Hopping Parameters

Institute of Brewing and Distilling Asia Pacific Section Wolfe, P. H. (2012). A study of factors affecting the extraction of flavour when dry hopping beer (Doctoral dissertation - OSU).

24hrs

Dry Hopping Parameters

Institute of Brewing and Distilling Asia Pacific Section

Dry hopping trial procedure

5% ABV un-hopped beer base used

Dry hopping added as hop pellets T90 or extracts

Temperature for all trials 4oC

Equilibration time 24 hours with stirring

Beer clarified by centrifugation and filtration

Hop aroma analysis by headspace SPME with GC-MS [1]

Non–volatile molecules not considered

Li, H., Liu, F., Kun-Farkas, G., & Kiss, Z. (2015). Quantitative Analysis of Flavor Volatiles in Beer Using Headspace Solid-Phase Microextraction and Gas Chromatography–Flame Ionization Detection (HS-SPME-GC-FID). J. Am. Soc. Brew. Chem, 73(3), 261-265.

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 8

● Single grower source (US, Oregon)

● Alpha acid content 8.0%

● Oil content 2.0%

● Composition:

Cascade hops

● Myrcene 58%

● Humulene 16%

● Caryophyllene 7%

● Farnesene 6%

● Linalol 0.6%

● Geraniol 0.2%

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 9

Cascade hops

Caryophyllene

Humulene

Farnesene

Myrcene

TIC

Linalol

Geranyl acetate Geraniol

Methyl geranate

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 10

Cascade hops

Caryophyllene

Humulene

Farnesene Myrcene

Linalol

Geranyl acetate

Geraniol

Methyl geranate

Geranyl iso-butyrate

EIC m/z 69

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 11

1. Ethanol 2. Ethyl acetate 3. 2-methyl-1-propanol 4. 3-methyl butanol 5. 2-methyl butanol 6. i-amyl acetate 7. Myrcene 8. Ethyl hexanoate 9. Linalol 10. Phenyl ethanol 11. Octanoic acid 12. Ethyl Octanoate 13. Citronellol 14. Geraniol 15. Phenyl ethyl acetate 16. Methyl geranate 17. Geranyl acetate

1

2

3

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5

6

7

8

9

10

11

12

13

14

15

16

17

Headspace SPME – GC/MS

Cascade single hopped beer

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 12

Pellet dose rate

Mean data from triplicate trials

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 13

Impact of hopping rate on concentration

mg/l

g/hl

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 14

%

g/hl

Impact of hopping rate on transfer rate

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 15 Pellet dose rate (g/hl)

Beer loss (%)

Impact of hopping rate on % beer loss

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 16

Increased hopping rates do not result in a linear increase in final flavour and aroma levels and can introduce undesirable flavours

Beer losses resulting from higher hopping rates have a significant impact on brewing economics

Alternative strategies such as the use of concentrated pellets or lupulin powders can partly mitigate these losses but brewers report handling problems

A greater understanding of the mechanism of hop aroma transfer from hops to beer has been used to develop a “hop aroma extract” approach, however at present this is on an individual product basis

Using a “hop extract” approach also preserves a-acid value

Trial conclusions

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 17

Properties of key hop molecules

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section

1. Ethanol 2. Ethyl acetate 3. 2-methyl-1-propanol 4. 3-methyl butanol 5. 2-methyl butanol 6. i-amyl acetate 7. Myrcene 8. Ethyl hexanoate 9. Linalol 10. Phenyl ethanol 11. Octanoic acid 12. Ethyl Octanoate 13. Citronellol 14. Geraniol 15. Phenyl ethyl acetate 16. Methyl geranate 17. Geranyl acetate 18. Caryophyllene 19. Humulene

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Headspace SPME – GC/MS

Solubility of hop oil molecules in beer

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 19

Partition of key hop molecules

Log Kow (n-octanol/water partition coefficient) is defined as the ratio of

the concentration of a molecule in n-octanol and water at equilibrium at

a specified temperature.

Log Kow values are unit less and are a relative indicator of the

tendency of an organic compound to adsorb to biomass

Values >4.5 are known to absorb strongly

The implication of the range of Log Kow values is that partition of these

molecules is key to the distribution in beer

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 20

Correlation of Log Kow values

Asia Pacific Convention 2018 | Wellington, New Zealand 21

Image from https://braukon.de/en/hopgun/

Hop extract solutions

Hop oil

scCO2

“Reverse phase chromatography” “Normal phase chromatography”

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 22

Increasing polarity

Chromatographic fractionation

Hydrocarbons - myrcene, humulene, caryophyllene

Esters - methyl esters C6 – C14

Epoxides - humulene epoxide II

Ketones - undecan-2-one

Alcohols - linalol, geraniol, humulenol II

Institute of Brewing and Distilling Asia Pacific Section

Hop oil fractionation

Pellets T90

Aroma fractions Ketones epoxides

Alcohols Hydrocarbons

linalool

geraniol

2-humulenol

Aroma molecules i-amyl-i-valerate

methyl geranate

geranyl esters

myrcene

humulene

caryophyllene

2-undecanone

humulene epoxide

caryophyllene oxide

Hop oil

Processing using “green” solvents including SFC (Marriott, R.J., Patents EP2865746, WO2015062745, 2015)

CO2 extraction

CO2 fractionation

Esters

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 24

Hydrocarbon fraction

humulene

caryophyllene myrcene

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 25

Ester fraction

, 10-Dec-2013 + 12:57:09R3-LC6

4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00Time0

100

%

0

100

%

ac063 Scan EI+

74

9.07e7

13.52

11.609.28

8.416.98

6.20

10.7813.04

13.85

15.24

17.57

ac063 Scan EI+

TIC

1.03e9

13.53

13.19

11.609.28

7.07 8.4110.89

11.3112.83

16.86

13.83

16.11

15.4014.30

17.74

17.51

18.60 20.7219.75

geranyl-iso-butyrate

methyl-4,8-decadienoate

Methyl-9-methyl decanoate methyl-5-dodecenoate

methyl heptanoate

methyl -6-methyl heptanoate

methyl octanoate

methyl -7-methyl octanoate

methyl -8-methyl nonanoate

methyl-4-decenoate

methyl geranate +

methyl decanoate

methyl nonanoate

2-undecanone

2-tridecanone

2-dodecanone (R)-linalol

geraniol

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 26

Carbonyl fractionation

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 27

Terpene alcohols fraction

(R)-linalol

geraniol

humulenol II

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 28

Dry hop profile creation

Cascade Pellets

CO2 extraction

CO2 fractionation

Oil reduced residue

CO2 extraction (E=93%)

a-acids

40% 11% 2% 47%

Cascade dry hop 500

E=95%

E=95%

E=100%

Esters Ketones epoxides

Alcohols Hydrocarbons

Cascade hop oil

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 29

Dry hop profile creation

Myrcene

Linalol Geranyl acetate Geraniol

Methyl geranate

Citronellol

Myrcene

Cascade pellets 500g/hl

Cascade dry hop extract 500

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 30

Commercial applications

US Craft Brewer (100,000BBL/annum)

Pilsner

4 hop varieties used, analysis and organoleptic evaluation resulted in hop aroma match

Beer flavour and flavour stability improved, 10% reduction in hop costs and 18% reduction in

beer losses. $150k/month savings

IPA (70 BU, 6.5% ABV)

Replacement of 5 hop varieties with single hop aroma extract, less cold storage required and

reduced inventory

Beer losses reduced by 27% and vessel occupancy by 12 days

Cost reduction $285k per annum

Other applications have used partial replacement to dry hops to reduce beer

losses while maintaining flavour profile

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 31

Conclusions

Transfer of aroma molecules from hops to beer appears to be predicted by a

partition model

As dry hopped beers reach mainstream volume more efficient strategies are

needed

Using hop extracts reduces or eliminates beer losses and makes efficient

use of hops as a-acids can be recovered

The use of aroma extracts has a neutral effect on BU values, no negative

impact from polyphenols and does not introduce DO issues

This alternative to dry hopping can be used in all beer styles, low alcohol

beers and NABs

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 32

Future work

Expand model to include a greater range of parameters, particularly

ABV and fermenter addition

Correlate analytical model with organoleptic data

Apply model to greater range of hop varieties and variety mixtures

Carry out more commercial brewing trials to generate more robust

data – we welcome participation from all brewers

Asia Pacific Convention 2018 | Wellington, New Zealand Institute of Brewing and Distilling Asia Pacific Section 33

Thank you for your attention!

ray.marriott@totallynaturalsolutions.com