A Look at Hop Utilization

AC Golden Brewing CompanyJason Meherg, Jason zumBrunnen

and Jeff Nickel

Overview

• History: what is bitterness and how do you measure it• Our test results• Your results: discussion time

What is Bitterness• International Bittering Unit– The measure of Iso-Alpha Acids and other

bitterness compounds in solution

– 1 BU = 1 mg/L or 1 ppm

– Alpha Acids vs Iso-Alpha Acids

– Beta-Acids and Essential Oils

Alpha Acids

• Soft resin fraction

o Humuloneo Cohumuloneo Adhumulone

• BB

• Beta Acids – Lupulone and the Ad-, Co-, and Pre- analogues

Beta Acids & Essential Oils

• Essential Oils– Myrcene, Farnesene, Linalool, and Carophyllene– Over 300 others and growing

Tinseth and DaneilsHop utilization 1.055specifc gravity

Boil timeTinseth aa% Daniels aa%

0 0 0.0650.089504 0.06

100.145977 0.15150.181609 0.15200.204092 0.19250.218277 0.19300.227228 0.24350.232875 0.24400.236438 0.24450.238686 0.27500.240105 0.2755 0.241 0.27600.241565 0.3650.241921 0.3700.242146 0.3750.242288 0.34800.242377 0.34850.242434 0.34900.242469 0.34 0 10 20 30 40 50 60 70 80 90

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

Alpha Acid utilization (13.5 Plato wort)

DanielsPolynomial (Daniels)Tinseth

Boil Time (minutes)

Alph

a Ac

id u

tiliza

tion

%

How to Measure Bitterness

• UV Spectrophotometric Method

• HPLC

UV Spec

• Industry proven wet method• IBU = Abs275 x 50

Automated UV Spec

• Skalar is automated version • Reduces human variable

IAA Spec Method

• Very similar to standard BU method• Measures Isomerized acids • Includes two additional separations with

methanol• Read at UV 255 nm• IAA = [(Abs255 x 96.15)+0.4]*3– Report IAA in mg/L

HPLC• Uses liquid mobile phase to separate

components of a solution• Mixtures injected under high pressure into

packed columns• Individual components resolved by adsorption

or desorption• HPLC Mass Spec a further advance– Reduces “chatter”

Which is Right?

• Development of method• Benefits and negatives to both• Cost• Measure of perceived bitterness • Oxidized co-products contribute

Our Turn

Hops go Where?

• Mash Hopping–Old technique– Enhances “kettle hop” character

• First Wort Hopping– Also been around a long time– 1995 Brauwelt paper brought it back

ACG BU Study

Brew Description OGCalc

KKO BUStart Boil 20 min End Boil Whirlpool

13 hop additons: 80 min, 20

min, WP15.0 134.0 n/a 49.19 94.7 98.01

2 Same as Brew #1 15.0 134.0 n/a 50.3 93.2 100.67

350% of WP hop added at

Mash15.0 134.0 16.2 62.17 98.97 116.46

450% of WP hop added at First

Wort15.0 134.0 38.6 91.86 109.97 128.84

BU Tests

ACG BU Study: Conclusions

Brew Description Start Boil 20 min End Boil Whirlpool

1 3 hop additons: 80 min, 20 min, WP n/a 49.19 94.7 98.01

2 Same as Brew #1 n/a 50.3 93.2 100.67

3 50% of WP hop added at Mash 16.2 62.17 98.97 116.46

4 50% of WP hop added at First Wort 38.6 91.86 109.97 128.84

BU Tests

Tests 1 and 2

80 min hop additon gives about 50% of BUs -close to calculated numbers

Whirlpool addition contributes about 5-7%

Note that the WP sample pulled at start of cooling: by end of cooling the BU had increased by 20

ACG BU Study: Conclusions

Brew Description Start Boil 20 min End Boil Whirlpool

1 3 hop additons: 80 min, 20 min, WP n/a 49.19 94.7 98.01

2 Same as Brew #1 n/a 50.3 93.2 100.67

3 50% of WP hop added at Mash 16.2 62.17 98.97 116.46

4 50% of WP hop added at First Wort 38.6 91.86 109.97 128.84

BU Tests Mash Hop Test:

Sample pulled at 85C after 120 min mash and lauter time

16 BU measure even though not at isomerization temps

Higher overall finished BU and WP utilization

Note: we used pellet hops for standard, not cones, so greater possibilty of lupulin transfer

ACG BU Study: Conclusions

Brew Description Start Boil 20 min End Boil Whirlpool

1 3 hop additons: 80 min, 20 min, WP n/a 49.19 94.7 98.01

2 Same as Brew #1 n/a 50.3 93.2 100.67

3 50% of WP hop added at Mash 16.2 62.17 98.97 116.46

4 50% of WP hop added at First Wort 38.6 91.86 109.97 128.84

BU Tests First WortHop Test:

Sample pulled at start of boil after 45 min lauter and heating time

39 BU measure

Higher overall finished BU, and substantially higher WP utilization

Note: we used pellet hops for standard, not cones, so greater possibilty of lupulin transfer

Home Brew Study

Sample IBUs D-Fraction Iso-co-Hum Iso-n-Hum Iso-ad-Hum Total IAAMash Hop 30.11 4.27 4.67 5.25 0.68 14.87 6.84 3.38First Wort Hop 43.98 4.04 10.97 14.86 2.15 32.02 19.98 14.5460' Addition 43.15 5.60 9.04 11.15 1.57 27.36 19.59 12.425 ' Addition 48.79 6.44 1.89 2.56 0.51 11.40 22.50 5.18WP Addition 49.22 6.47 2.51 4.91 0.52 14.41 22.45 6.54

Utilization by BU

Utilization by IAA

Dry Hop Study

Sample IBUs D-Fraction Iso-co-Hum Iso-n-Hum Iso-ad-Hum Total IAA IBU * 0.8513A - Pre DH 35.97 2.91 8.92 16.21 1.51 29.55 30.62A - Post DH 46.37 13.77 12.19 20.04 2.15 48.15 39.47B - Pre DH 22.25 2.51 4.90 10.16 0.97 18.54 18.94B - Post DH 34.29 10.62 6.07 11.08 1.23 29.00 29.19C - Pre DH 58.73 26.79 10.84 12.16 1.51 51.30 50.00C - Post DH 60.60 51.75 13.35 12.52 1.58 79.20 51.59

Special Thanks to:

AC Golden: Fletch, Kent, Ben and ChrisDr. Bob

Dr. David RyderRyan Pikna

Jaimie Lowe