QC for Small Brewers Made Simple

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QC for (Small) Brewers Made Simple

• Chris White
• MBAA District Mid-South
• December 2008

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Why Test???

• Small breweries, single brewer
• Selling beer on site
• Already too late when making beer?
• Reusing yeast?
• Find the source of the problem think like a
  microbiologist

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Lactobacillus
Pediococcus
Acetic Acid Bacteria
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OR- poor fermentation
Days
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Pub Brewies

• Small Brew Pub-
• lt 1000 bbls of beer produced per year.
• gt90 sold on-site, mostly from serving tanks.
• All draft, no bottles.
• Large Brew Pub (a)-
• Up to 3,000 bbls of beer produced per year.
• Limited distribution to local area, gt50 sold
  on-site.
• Bottles beer for distribution

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Small Regional Breweries

• lt 3,000 bbls of beer produced per year.
• All off-site distribution
• Primarily kegs with limited bottle distribution

-Very limited staff/Very limited time Very
limited distributed
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Mid-size Regional

• 3,000 to 30,000 bbls of beer produced per year
• Distributes to local and surrounding areas
  roughly within 800 miles
• Bottles and kegs

-Limited staff/limited time -Wider distribution
increases risk -Limited control of distributed
product Size of production allows for QC space
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Large Regional

• 30,000 to 100,000 bbls of beer per year
• Multi-State distribution through numerous
  Distributors

Macro

• -Wide distribution area high risk
• -Opportunity for neglect of product
• -Large staff, large space large batch size
  requires thorough QC program

• gt100,000 bbls of beer per year

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Create a QC Plan
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How we do it for Cheap?

• Sensory, sample panel
• Forced Wort Test
• Microscope

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Forced Wort Test

• Sterilize sample cock with isopropanol and flame
• Obtain wort sample cleanly into sterilized
  container-tube, bag, bottle.

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Forced Wort Test

• Incubate in a warm area for several days. Optimal
  temperature is 30ºC.

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Forced Wort Test

• Results
• Clear Beer is clean
• Cloudy wort or wort with bubbles bad news
• Can analyze or miniferment with the contaminant
• How long does your wort stay clear?

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If You Have More Money

• Basic Testing Supplies
• Selective Media
• Incubator
• Anaerobic Chamber
• Pressure Cooker
• Microscope

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Microscope
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Hemacytometer
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Hemacytometer- Full Grid

• This photo shows the 25 squares seen with the
  microscope at 10X power.
• Check for uniformity of cells. If okay, you can
  use the quick, 5 square method count.

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Establishing a Counting Protocol

• Use the same counting protocol for all 5 squares-
  Cells touching or lying on the top and right
  triple boundary lines are not counted, whereas
  cells touching or lying on the bottom or left
  triple boundary lines are counted.
• Yeast buds emerging from the mother cell are
  counted as separate cells if the bud is at least
  one-half the size of the mother.

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Other notes

• Yeast cells are easily seen at 40X power.
• You may also notice trub in your viewing field
  that may stain.
• Trub can be seen in this square at top center and
  mid center.

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Viability protocol

• Dead cells will stain dark blue
• Cells that are clear or pale blue in color are
  considered alive.
• Some budding cells will stain dark blue, but they
  are not dead! Buds are busy with growing
  metabolism and not extruding the dye.

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Square 1

• Keeping with the counting protocol, you should
  have counted
• Total cells 69
• Dead cells 1

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Calculating Your Cell Count

• Take the total of cells you counted in the 5
  squares. In this case 302
• Multiply cells 5 squares by 5 to generate the
  number of cells in 25 squares? 302 x 5 1,510
• Determine your dilution factor of your sample.
  In this case 1100
• Volume in Hemacytometer chamber is 1/10,000 ml
• Yeast cells/ml Total cells in 25 squares x
  dilution factor x (1 x 104)
• 1,510 x 100 x (1 x104) 1.51 x109 or 1.51
  billion cells/ml

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Calculating Your Yeast Viability

• of live cells total number of cells x 100
  viability percentage.
• In this example 7 dead cells total
• 295 302 x 100 97.7 viable

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What do you do with this?

• 1.51 billion cells/ml, 98 viability
• Calculate volume for pitching
• Confirm pitching rate- what is your rate?
• Track fermentation progress
• Bottle conditioning beer
• Yeast health
• Troubleshooting
• Become a better brewer!

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Starting a Lab!

• 15ml tubes for dilutions HLP testing
• Sterile serological pipets with bulb or transfer
  pipets
• Pyrex glass flasks or bottles
• Media
• Microwave
• Sterile petri plates
• Portable propane flame
• Plate spreader
• Incubator
• Sink

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Micro testing basics

• Aseptic technique
• Use a flame isopropanol when possible
• Used sterilized equipment
• Avoid air drafts and foot traffic

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Setting Up a Testing Regime

• Keep it simple or you wont do it
• Every brew Wort Test test pitching yeast
• Every week Brewery tanks
• Post CIP Swab test

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Media Options

• Purchase ready made plates or pour your own
• Best bet for anaerobic organisms- HLP

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Media Options

• Best bet for aerobic organisms and wild yeast-
  WLN, WLD.

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Testing Pitching Yeast

• Requires dilutions
• Test for aerobic bacteria, anaerobic bacteria,
  wild yeast
• Results in 1 5 days

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Plating your samples

• Wipe down counter with isopropanol
• Isopropanol on hands/gloves
• Label plates with sample type and date
• Work near flame and transfer 0.1ml 0.25ml to
  plate. For HLP tube transfer 0.5ml to 1ml
  sample.
• Spread sample evenly on plate
• Let sample dry on plate for 20 minutes
• Once dry?turn plate upside down and incubate in
  warm area.

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Incubating samples

• Aerobic with air. Primarily looking for
  bacteria such as Acetic Acid bacteria and also
  contamination by wild yeast.
• Anaerobic bacteria without air. Primarily
  reveals Lactic acid bacteria.

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What if something grows?
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What will you do?