Sour Beer, Why? How?

Mr. Hayden Mokaraka & Dr. Sylvie Van Zandycke

Lallemand Brewing

This Presentation

• Introduction

– Sour beers

– Microbes

• Lab trials with 7 Lactic Acid Bacteria

• Brewery trials in Australia with chosen

bacteria

History & Styles of Sour Beers

• Sour beer styles have existed for centuries

• What do we mean by Sour beer?

• History and heritage of sour beers have been based

in Europe, including:

Berliner Weisse

Gose

Lambic

Flanders Red Ale

Modern Sours

• Growth in Belgian sour imports in 90’s influence US

• Based on historic styles

• Huge diversity in sour styles, flavors and creativity

Key micro-organisms in sour beer

Wild Yeast: Brettanomyces

• Can utilize broad range of

sugars (inc. dextrins)

• Diverse sub species

• Does not contribute a lot

of acidity on its own

• Slow acting

Pediococcus species

• Slower than Lacto to sour

• Greater hop tolerance

• Cannot reduce Diacetyl/Emulates off flavors

• Sharper and harsher taste

• Can reduce pH <3.0

Lactobaccilus species

• Primary souring bacteria

• Diverse range of sub species

• Temperature sensitive (c.30-49C)

• Softer and tangier lactic acid

• Lowers pH to c.3.3-3.6

HOMOFERM. FACULTATIVE

HETEROFERM.

OBLIGATORY

HETEROFERM.

L. acidophilus L. casei L. brevis

L. delbrueckii L. curvatus L. bunchneri

L. helveticus L. plantarum L. fermentum

L. salivarus L. sakei L. reuteri

L. pontis

R&D Trials

• 1g/hl except for L. plantarum A 10g/hl

• 500ml wort fermentation

• Achieve pH 3.5 or lower in <48 hours

• Achieve high lactic acid vs low acetic

concentration

• Fermentations at 3 different temperatures

• Gravity and pH measurement daily

• Acid analysis by HPLC

• Sensory assessment of samples by panel

R&D Trials: Fermentations (20C)

R&D Trials: Fermentations (30C)

R&D Trials: Fermentations (40C)

Lactic acid production

Acetic acid production

Sensory characteristics

Conclusions

• L. plantarum demonstrated the fastest pH drop at

20/30/40C

• Most LAB in this study struggled at 50C (not

shown)

• Ideal temperature of 30/40C

• High acetic acid at 20C

• L. helveticus was more active at 40C – high levels

of lactic acid – highly sour

L. Plantarum A was selected for further trials

Sources of LAB

• Laboratory (pure or mixed

culture)

• Bottle culture

• Nature

• Yogurt

• Un-mashed grains

• Now also in dry form

Application and techniques for

souring Mash Souring

• Liquor, grain adjustment

• Bacteria from grain or inoculated

• 2 – 3 days

Kettle Souring • Wort innoculated with LAB

• 2 -3 days

Co-fermentation • Mixed sacc, LAB & Brett

• Typical fermentation time

Barrel/Foeder/spontaneous ageing • Often in wood (or Keolschip)

• Mixed spectrum of microflora

• Greater complexity

Queensland Trials at Coral Sea Brewing Co

Scope

Make 1000L of soured wort and

experiment to produce 4 different

sour beer products.

Pictures of day 1 - the brewing

Sep 2017

Kettle sour process

Create a Building Block

• Mash

• Lauter

• Heat to sterilize

• Cool to 40 degrees

• Pitch Bacteria

• Monitor/Wait for

acidification

• Desired PH achieved –

3.35 took 18hrs (from 5.2

start)

• Boil/Hop continue as

normal

Photo after 18 hours

Fermentation

Batch split 2 ways

1. 500L Pitched with

Diamond Lager Yeast

2. 500L Pitched with

Munich Classic Yeast

(German Wheat)

Tasting notes, Lager - very

clean, sour finish.

Wheat - banana / clove

finish sour/tart balanced

Then we split the two batches again!

October 2017

• 230L of Lager into an Ex-

Whiskey Barrel

• 300L Wheat into an Ex-

Rum Barrel

• 100L Remaining Wheat

300gms Salt 10 kg of

muddled lemon/lime

added Gose Style

• 200L Remaining Lager

had 10kg of muddled

Strawberries added

Berliner Weiss Style

Final Tasting notes

In Tank/keg - November

2017

• Wheat Strawberry –

Fresh fruit strawberry

aroma, yummy!

• Lager Gose – Citrus,

salty (top end salty)

herby, tequila, sour

finish

In barrel – January 2018

• Lager/Whiskey - clean

and balanced slightly

sour, sl buttery.

• Wheat / Rum – Bold rich

barrel oak, rum, vanilla

but well balanced. Sl

oxidized but it works

ok.

Summary

• Sour beer is continuing to increase in interest with

consumers and brewers

• Application of specific LAB is an important factor to

obtain your flavor goals

• Potential of experimentation – house blends

• Questions???

Thirsty anyone? *** Please come see the differences of the sour beers

for yourself! ***