Credit to: Ed Hamrick & Mike Brennan 1. Basics Hop structure - - PowerPoint PPT Presentation

Credit to: Ed Hamrick & Mike Brennan

• 1. Basics
• Hop structure
• History
• Hop forms, growing areas
• Bitterness vs Aroma hops
• How to calculate bitterness
• 2. Deep Dive into Flavor & Aroma
• Essential Oils
• Thiols
• Maximizing hop expression

Hops are the cultivated female flowers of the perennial humulus lupulus vine, a relative of cannabis.

• The flowers are green cones with

yellow lupulin glands at base of bracteoles

• Bracteoles (leaves) attached to the

central stem, the strig

• Lupulin resin contains alpha

acids, beta acids, and essential

• ils:
• A. Bitterness
• B. Flavor
• C. Aroma
• Alpha acids expressed as

percentage of weight

• Male plant used for breeding
• nly

Hops provide the bitter counterpart to the sweet malt in beer. Hops act as a preservative, aid in kettle coagulation, and help in head retention.

• Prior to use of hops, herbs, seasonings, and spices

were used to balance sweetness.

• Use of hops from 736 A.D. in South Central

Europe

• Widespread usage in the 16th Century when

legislated as required in the Reinheitsgebot (the German Beer Purity Law) in 1516

• Introduced into U.S. in 1629 by colonists
• Major production in the Pacific Northwest US

(Washington, Oregon, and Idaho), Germany, New Zealand, & Czech Republic

Hop Varieties: The Spice of Life

• Hop varieties are associated with particular beer styles:
• English Ales: E. Kent Goldings, Fuggles
• European Styles

Bohemian Pilsners: Saaz German Pilsners: Tettnanger, Hallertauer, Mittelfruh, Spalts Altbiers: Spalts, Hallertauer Marzen / Octoberfest: Hallertauer, Saaz, Tettnanger

• American Styles

American Pale, IPAs: Cascades, Centennial, Columbus, Chinook California Common: Northern Brewer

• New Hops (blurring the lines)

Citra, Mosaic, Simcoe, Amarillo, Sorachi Ace Newer: Eukanot, Mandarina Bavaria, Safir, Cashmere

• Growing regions determine hop

character also

• Hallertau district north of Munich grow hops for

beers of Munich

• Zatec area near Pilsen grow Saaz hops
• Victoria, Australia grow Pride of Ringwood hops
• County Kent, England grow E. Kent Goldings
• Pacific NW grow Mount Hood, Willamette,

Rainier

• British Columbia, Canada grows Olympic hops
• Classic hop varieties grown in different climates

exhibit different characteristics than hops grown in native region

Hop Form Follows Fashion

• 1. Whole hops / loose hops are the most natural form

Advantages

• Float on surface allowing easy siphoning
• Form a filter bed
• Deliver original unprocessed hop compound

Disadvantages

• Float - lose some contact with wort
• Greater exposure to O2 could lose quality quickly
• Useful resin and oils less than 15%
• Loss of wort when removing hops
• Bulky and expensive to ship, handle, and dispose

• 2. Plugs (type 100 pellets) are whole hops pressed into ½ oz. disks

Advantages

• Closest to whole hops
• Reduced volume
• Vacuum packaging
• Used for dry hopping and hop back

Disadvantages

• Limited selection of hops
• Processed in England, shipped to U.S. could affect

freshness

• Difficult to separate into increments less than½ oz.
• Compression causes lupulin glands to burst, causing
• f volatile hop aromatics and increased oxidation

Hop Form Follows Fashion

• 3. Pellet (type 80) - hops ground into powder, batches from several

hop bales are blended for consistency & pelleted through a die

Advantages

• a. Easy to measure
• b. Reduced volume
• c. Greater storage stability
• d. Consistency
• e. Enhanced utilization
• f. Sink-maximum contact with wort
• g. Contribute 10% more alpha acids due to surface area

Disadvantages

• a. Difficult to avoid when siphoning
• b. Additional processing may affect hop compounds

Hop Form Follows Fashion

• 4. Hop extracts involve milling, pelleting, remilling to spread the

lupulin, passing a solvent through a packed column to collect resin, removing the solvent to yield a “pure” resin extract

Advantages

• a. Reduced bulk
• b. Improved storage
• c. Standardization and

consistency

• d. Increased utilization
• e. Reduced wort losses

Disadvantages a. Higher cost per bitterness unit b. Immediate availability of essential

• ils to boiling wort may be

detrimental to flavor c. Solvent residues may be present d. Heating to remove solvents may alter aroma profile

Hop Form Follows Fashion

Two Basic Categories

• 1. AROMA HOPS
• a. Low alpha acids
• b. High beta acids
• c. Good aroma oil profile
• d. Used as finishing hop
• i. Late kettle additions
• ii. Dry hopping
• e. i.e. Noble hops
• i. Saaz, Spalt, Tettnanger, Hallertauer Mittelfruh

• 2. BITTERING HOPS
• a. High alpha acids
• b. Low beta acids
• c. Less refined flavor and aroma
• d. Common bittering hops
• i. Brewers Gold, Nugget, Chinook, Magnum

Eroica, Galena, Bullion

• 3. DUAL PURPOSE HOPS
• a. Northern Brewer, Columbus, Cluster, Perle,

Centennial

All Hail the Hop!

Anatomy and composition of the hop cone adapted from Benitez et al. and Biendl. From MBAA TQ vol. 56, no. 1, 2019

• The alpha acids in hops

provide most of the bitterness.

• Humulone, Cohumulone,

Adhumulone, Prehumulone, Posthumulone

• Proportions vary in hop varieties
• Insoluble alpha acids are isomerized

into soluble, stable iso-alpha acids in a vigorous boil

• Bittering hops are most efficient at yielding

Iso-alpha acids with 60 to 90 minutes of vigorous wort boiling.

• Beta acids also add some bitterness
• Oxidation products add bitterness and are soluble
• Oxidized beta acids are not as bitter as iso-alpha acids
• Humulinones (“Oxi-Alpha”) are oxidized alpha acids

(from dry-hopping) – new research shows similar reduction over iso-alpha acids but are “smoother”

• An IBU is 1 mg/liter of iso-alpha acid in

solution or (ppm)

• Measures the concentration of isomerized

alpha acids in finished beer

• Factors affecting the IBU include length of

boil, wort pH, wort strength, age and condition of hops, hop form, and hopping rate, hop bags

• Relative IBU does not always translate to

perceived bitterness in the beer

• Water chemistry, particularly carbonate,

sulfate, and chloride levels affect bitterness as well as the degree of attenuation

Measuring Bitterness (IBU - International Bittering Unit)

Empirical testing by Jack Rager IBU = [7489 * (W*A*U)] / V

7489: conversion from mg/L to oz/gal W: oz of hops A: alpha acid % as a decimal U: utilization factor V: volume of beer in gal

Mods by Glenn Tinseth, Mark Garetz, et. al.

• nly estimates, actual needs

laboratory testing

For OG = 1.050

• Reduced contact time of

hops with boiling wort

• Increasing wort gravity
• Use of whole hops instead
• f pellets
• Increasing the hopping

rate

Utilization is reduced by:

• Use of hop bags in the boil
• Use of old hops
• Decreasing wort pH
• Use of more flocculent yeast
• Filtering beer
• Oxidation of finished beer

IBU Chart by Style

• 1. Lambics

<10

• 2. Lite American Lager

8-12

• 3. Blonde Ale

15-28

• 4. Brown Porter

18-35

• 5. Octoberfest

20-28

• 6. Kolsch

20-30

• 7. Ordinary English Bitter

25-35

• 8. Dry Stout

25-40

• 9. Bohemian Pils

35-45 10.American IPA 50-75+ 11.Imperial IPA 60-100+ IBU/OG Ratio 0.1-0.2 0.1-0.2 0.3-0.5 0.4-0.6 0.3-0.5 0.4-0.6 0.6-0.9 0.6-0.9 0.6-0.9 0.8-1.0+ 0.7-1.0+

1 ppm Iso-alpha Acids 0.7 IBU 1 1 ppm of Humulinone 0.6 IBU 0.66 1 ppm of Alpha Acids 0.6 IBU 0.1 1 ppm of Beta Acids 0.4 IBU 0.05 1 ppm of Xanthohumol 0.07 IBU Not Bitter The IBU Calculation Does Not Work For Dry Hopped Beers The Isoalpha acids, Humulinones, Alpha Acids & Beta Acids in dry hopped beers get extracted into the isooctane layer and absorb light at 275 nm & at different intensities, thus interfering with the IBU test. Each hop acid has a different bitterness therefore you cannot correlate the IBU test to sensory bitterness. IBU Response Relative Bitterness Factor Iso-Alpha Acids HPLC can accurately measure the concentration of isoalpha acids, humulinones, & alpha acids in beer allows one to calculate the bitterness of NEIPAs.

Step Away from The IBU!!!

› IPA Evolution – in last decade IPA alone has spurred:

–IBU War/Weaponized IPA 90+ IBU –Fruit IPA

› Complementary to fruity hop varietals

–‘Session’ IPA

› Large late-hop additions

–Hazy IPA

› The anti-IBU › Massive late-hop additions › Most-entered 2018 GABF competition category (704+)

– Exceptionally short shelf life

–Brut IPA

› The anti-hazy › Amylase

–??? IPA by Christmas?

• Essential oils
• 0.5 to 4.0 % vol/wt
• Over 250 components of the

essential oils

• 22 of those (generally called

Terpenes & Thiols) pinpointed as indicators of hoppiness

• Myrcene (pungent, woody, piney)
• Oxygenated Terpenes: Linalool,

Germaniol (geraniums), Limonene,

• Trespinol. Humulene (elegant),

Cayophyllene, Farnesene.

• Floral / estery compounds
• Citrus / piney compound

Flavor & Aroma

• Thiols (aka Mercaptans)
• Very, very powerful aromaticcompounds
• Less than 1% of hops

– 3-mercapto-hexanol (3MH) – Guava, Tropical – 3-mercaptohexyl acetate (3MHA) – muscat, passionfruit – 4-mercapto-4-methyl-pentan-2-one (4MMP) - black currant – 4-methyl-4-sulfanylpentan-2-one (4MSP) - black currant, mango

• Are there negative thiols?
• YES, and you’ve probably experienced them before
• Lightstruck/skunked beer - 3-methylbut-2-ene-1-thiol

› Why we use brown bottles!

• Dimethyldisulfide, S-methylthio-isovalerate, S-

methylthiohexanoate ‘onion’, ‘garlic’

• - Cabbage

Flavor & Aroma

So Where Do I Find These?

• Geraniol-rich hops
• (floral, rose,

citronella)

• Aurora
• Bravo
• Cascade
• Centennial
• Chinook
• Citra
• Denali
• Mosaic
• Motueka
• Styrian Golding
• Linalool-rich hops
• (floral, citrus,

lavender, Fruit Loops)

• Amarillo
• Bravo
• Cascade
• Centennial
• Citra
• Glacier
• Millennium
• Mount Hood
• Nugget
• Pacifica
• Willamette
• Hops containing

Thiols like 4-MMP – Blackcurrant, gooseberry, sauvignon blanc

• Apollo
• Bravo
• Cascade
• Centennial
• Citra
• Chinook
• Cluster
• Ekuanot
• Eureka
• Hallertau

Cascade

• Mosaic
• Simcoe
• Summit
• Myrcene-rich hops -

(green, herbaceous, resin, pine, dank*)

• Cascade
• Centennial
• Chinook
• Citra
• Amarillo
• Columbus*
• Simcoe*
• Apollo*
• Galaxy*
• CTZ*

Hop Chart

Link to excel sheet listing general flavor profiles of various hops, plus details on %

• f alpha acids, beta acids, and major essential oils

Hop Rankings

Another excel spread sheet with rankings of hops based on amounts of alpha acids, beta acids and various essential oils, sortable by column

• Many components are volatile and do not

survive in extended boiling times

• Maximum oil utilization is 10-15%, which

decreases with increased boiling time

• Flavor and aroma hops are added during last 30

minutes of the boil

• Flavor hops for last 10 to 30 minutes
• Aroma hops for last 5 minutes
• . . . Or later

Maximizing Your Hop Expression

› Categorize your hops into late kettle/hopstand additions,

active fermentation additions, and dry hops

› Late kettle additions will lose the most volatile substances

–BUT – some ‘bittering’ hop additions DO contribute to aroma

› Hopstand (whirlpool) or Hopback (thru-put)

–180 degrees or cooler, 20-50 minutes –Try multiple stepped additions as wort cools

› Active fermentation – biotransformation, ‘juicy’

flavors/aromas

–Some pro brewers begin 24-48 hours after pitch – yeast have consumed most free oxygen –Some brewers wait until about 8 to 20 gravity points before end of fermentation –Avoid vigorous CO2 production – CO2 stripping?

› Dry hop – after complete fermentation

• Filled with fresh hops; hot wort flows

though hops and chilled before entering fermenter

• Volatile hop aroma compounds are

extracted

• Produces flavor / aroma profile

between late kettle additions and dry hopping

A hop back is a reservoir connected in-line between the kettle and counter flow chiller

Hops Added During Fermentation? The Mysteries of Biotransformation

› Processes within yeast cells which alter the structure

• f some hop aroma compounds

› Convert an odorless or less potent aroma compound into one with more odor or more potency

• Gerniol converted into citronellol
• Linalool converted into terpineol

› Yeast strain-dependent. Different yeast strains have unique pathways.

• β-glucosidase plays a big factor

› Influenced by temperature, pH, presence of cofactors › A few pathways have been described, still difficult to predict

The Mysteries of Biotransformation

• Dry hopping is adding hops after the boil

to the secondary fermenter or serving vessel to add aroma

• After fermentation slowed and little CO2 is driven
• ff the wort to prevent volatile hop oils being

scrubbed away by CO2.

• Early in the fermentation may cause hops on

bottom of fermenter to be covered with yeast, which results in inefficient extraction of aroma.

• Addition after fermentation allows contact with

alcohol which helps prevent infections.

• Length of dry hopping is dependent on

temperature

• Ale temps: 7 to 14 days
• Lager temps: 14 to 21 days
• Hops should match style of beer
• Methods of dry hopping
• Add hops directly to fermenter
• Hops in a sanitized hop bag with marbles
• Steep hops in white alcohol and water solution

for several days and then add to fermenter

• Add hop oil to fermenter

Multi-addition: 3-5 days per addition 4 - 8 g/L

First Wort Hopping

• An old German technique used for hop

centered styles like Pilsner, consists of adding hops to the sweet wort runnings from lautering

• Higher pH extracts finer qualities of hop flavor
• Hops are kept in wort throughout the boil and contribute

a more refined smoother bitterness and a fresh hop flavor and aroma

• Process is not completely understood;

possibilities include:

• formation of stable complexes or esters
• removal of undesirable, volatile components

Measuring flavor and aroma potential of hops

• Total hop oil percentage is questionable

measure

• Major components of hop oil beta-pinene,

myrcene, beta-caryophyllene, farnesene, and alpha-humulene are not found intact in beer

• Fermentation and oxidation products of these

components like humulene epoxides and diepoxides are contributors to hoppy flavor and aroma

• Some hop oil components do survive into the beer

intact with dry hopping

SUMMARY I

› Iso-Alpha acids will contribute to bitterness in the boil – Utilization › Alpha acids will contribute to bitterness from whirlpool/hopstand additions – slower utilization (hard to predict) – so reduce your bittering additions › Oxizided alpha acids (humulinones) may contribute some increased bitterness in the dry hop (hard to predict) › Hop-derived tannins/polyphenols may contribute some increased bitterness, and also contribute to haze-binding (yay NEIPA!)

SUMMARY II

› Hop essential oils volatilize in boil › More will remain in hopstand/whirlpool › Try active-ferment additions anywhere from 1-2 days after pitch to about 1.020 gravity to maximize biotransformation processes (chances) › Dry hop to nail down the raw terpene aromas › Get your water chemistry under control › Choose a good yeast and use a fresh pitch › A mash pH of 5.2 and proper water chemistry means final beer pH of 4.5 to 4.65 – the happy range for hop expression, biotransformation

› There are more bittering, flavor, and aroma contributions from hops than we traditionally describe (it is very complex) › There is no easy one-size-fits-all method to shaping › Biotransformation is still very mysterious

• Yeast interaction with hop-derived constituents can be

significant

• Yeast strain with same hops can produce very different

aromas and flavors _ Continue to EXPERIMENT ON YOUR OWN and keep discovering new hop expressions Continue homebrewing because it will never stop being FUN!

SUMMARY III