winter conference 2011 -practical yeast propagation. with john mallett

8/17/2019 Winter Conference 2011 -Practical Yeast Propagation. With John Mallett

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Practical Propagation

MBG/MBAA

2011 Winter ConferenceKalamazoo MI


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Why you don’t you want to implement

any of the information in this talk?

• Expensive!

• Time intensive.

• Trial and error optimization required

• Stringent sanitation and QC is a requirement.


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Yeast Source Options

• From Prior Brews

• Receive from a friendly local brewery • Dried Yeast

• Purchase Pitchable & Propagate (in tank)• Grow from slant in house, propagate in tank

• Complete “Single Cell to Plant Scale”Propagation Program using Dedicated

Propagation Equipment.


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Slurry vol 1600 ml

Slurry conc. 2,500 mcells/ml Total cells 4,000,000 mcells

Desired Pitch conc 8 mcells/mlCalculated wort vol. 5.00 hl

Wort vol 7 bbls821 liters

Pitch conc 4.87 mcells/ml


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Dilute 4X at:

3o P drop,

2 days or

30-40 X 106 c/ml


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Drauflassen

• flowing on to

• A portion of the propagated media is left behindand fresh wort is added. The propagation starts

again and desired cellular densities are achievedrapidly.

• Blend off Draufloss at 10% or less


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Why didn’t it work for us?

• Insufficient quantities from appropriate sources

– 6 Yeast source beers – 2 Stouts (too dark)

– 4 Types have excessive starting Plato

– 1 Style Micro-compromised (Dry Hop)

– 5 Products use other yeast strains

– Developed Logical Test Spreadsheet for Sales Dept.• Overall: Not fast enough, Not enough yeast,

Potential flavor matching issues


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Louis Pasteur Gooseneck Flask


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Propagation Goals

• Acceptably high cell counts

• High viability (>95%)• Good vitality or metabolic activity with (high

glycogen and sterols levels)

• Free of contaminating microorganisms

• 110-150 mcells/ml of healthy yeast

• Yeast Health is more important than Cellular

Mass


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Yeast Nutritional Needs

• Sugar source

• FAN source (trub, yeast, wort)• O2

• Trace elements: Zn, Cu, Mg,


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Propagation Considerations

• Propagation Temperature• Sugar Spectrum

• Wort: 7-12oP• Yeast Nutrient

• Low CO2 – Aeration (with air!) – Nucleation sites

• Sterile Air/O2 (0.22um filter)• Linseed Oil

• Foam: Antifoam, 50% headspace or defoamers• 0.5ppm Zn (zinc sulfate heptahydrate)


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Flavor Concerns

• Oxidized flavors

• Esters – While yeast is in growth phase it consumes more

acetyl CoA (ester precursor)• Blending may be required


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Dilution Ratios

• Why?

• 6 X rule• Exceptions


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Sample Methods: Stepped Propagation

100 ml 1 liter 15 gal 2 Bbl 8 Bbl 50Bbl

Diluting to 10 mcells/ml at each move

10 ml 1 liter 1 Hl5 Hl18 Hl 200Hl

E. flask

C. Flask

2.5 Bbl

10 Bbl

?4X volume increase at each move

Each is a 7 day ferment, so X weeks to prop up

Mid-Plato wort & 12 ppm of O2 at each addition


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Identifying the Ideal Yeast

Propagation Technician:

Diagnosis: Paranoid

with ObsessiveCompulsive

Disorder

(manifested through

continuous cleaningbehavior)


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Sanitation critical

• Bacterial growth rate is much (4X) higher than

yeast• Propagator maintains ideal growth conditions

• Ample sugars, high pH, high O2, low CO2 etc.• Labwork to verify that propagation is clean

• Differential Media Plating & ATP PCR verification


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Labor

Time

Growth

Time Task Container

1 72 Prep & streak Culture plate

1 36 Innoculate 90 ml Vial

0.5 48 Innoculate 500 ml Flask 6.6 :11.5 36 Innoculate 20 liter Carlsberg Flask 40 :1

0.25 24 Innoculate 7 Bbl Prop Tank 42.1 :1

0.25 24 Innoculate 18 Bbl Prop Tank 3.6 :1

2 Micro Plating & Assay

6.5 240 Total (Hours)

Volume

Pitch

Ratio


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Task Time

Labwork to prop to 20l 390

Sanitize/Setup Prop System 120

Wort to Wort Tank 30

Panel/Program Changes 50 Wort & Inoculum to Prop Tank 40

Topping Wort Charge #1 30Pitch 30

Clean 270

(16 Hrs) Total 960


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Purchase 7 Bbl Pitchable Slurry $ 258

+ Shipping

Labor: 16 hours @ $22/hr = $ 352 Wort & Lab Supplies $ ?

Propagator $120,000


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Equipment Design & Operation

• Simple, stepped size fermentations

• Pumping/mixing • O2 Additions/Control

• Substrate (wort) Additions/Control


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Carlsberg Flask

• 25 liter net

• sterilize withheat

• pitch with 200ml lab prop

• aeration lance

• ~ $6,000


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Respiration, Fermentation,

Crabtree & Glucose• Glucose > 0.4% induces Crabtree effect

• As low as 0.2 g glucose/liter?• Incremental Feeding (Zulauf Process)

• Used for Baker’s yeast propagation• Up to 2.5 X as much yeast as batched process

– 12o

P is 120g extract in 880g water – 10-15% of extract is glucose/fructose

Fed Batch Difficult: must Control pH, O2 & Sugars


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Newlands YPS

• 60, 120, 240 liter systems

• $26-38,000• Operates as incremental feed system

• As yeast consumes sugars in the wort more isconstantly added

• Ideally, the propagation slurry Plato stays lowand the cellular concentration is high.


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Starter Volume 120 litersCell concentration 120 mc/ml

Wort Addition 15 Bbls Total Volume 1880 liters

Pitch rate 7.7 mc/ml


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Frings

• 1.25, 25, 200 hl working volumes

• Aeration device, Mechanical defoamer• Vessel DO controlled to ~ 2ppm

• Growth of up to 12 X in 24 hrs• Cell count of 150-200 X 106 /ml possible

• Pitching rate of 1-1.5 l/hl• ~$80-90,000 for 25 Bbl (net) system


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Esau Huber

Alfa Laval/Scandi Brew • $100-150K for 5-30 hl

• swing panel, pump, plc,• Mixers, Pumps, Aeration Lance, Turbojet


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L b C ti P ti


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Task Time Wort Charge #2 30Labwork to prop to 20l 390 Wort 3 to Wort Tank 30

Sanitize/Setup Prop System 120 Pitch #2 30

Wort 1 to Wort Tank 30 Wort Charge #3 30Panel/Program Changes 50 Wort 4 to Wort Tank 30

Wort & Inoculum to Prop Tank 40 Pitch #3 30

Wort Charge #1A 30 Wort Charge #4 30 Wort 2 to Wort Tank 30 Pitch #4 30

Pitch #1 30 Clean 270

Total: 1230 Hours: 20.5

Labor: Continuous Propagation

Pitch 350 Bbl/day, 4 cycles


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Cell concentration 126 mc/ml Wort to pitch 350 Bbls

41,067 liters

Desired Pitch rate 6.5 mc/ml

Pitch Volume 2,119 liters

18.06 Bbls


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Starter Volume 7 BblsCell concentration 126 mc/ml

Wort Addition 18 Bbls

Pitch rate 35 mc/ml


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winter conference 2011 -practical yeast propagation. with john mallett

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