Lesson 1 - Introduction to Hygiene

We will now provide a brief overview of some of the topics covered in this unit. 

Lesson one

In this lesson, we will focus on topics such as:

• Design concepts of hygienic CIP systems.
• The different types of soils encountered in brewery environments and their nature.
• The four factors of cleaning and their interactions.

Figure: The four factors of cleaning (Sinner’s Circle)

• The nature and functioning of detergents and disinfectants and how they are enhanced through additions.
• The make-up, action, additives, and use of caustic soda, acids and disinfectants.
• Design and selection of CIP plants and their applicability for different brewery configurations, covering single and multi-use systems.

• The detailed operation of the CIP plants: demonstrating an understanding of the design principles.
• The selection of spray head devices for vessel cleaning, linking these to the efficiency of cleaning as well as water and energy use.

Figure: Types of spray heads

• The validation procedures applied to brewery CIP processes.

 

Lesson two

In the second lesson, we will focus on microorganisms found in brewing, including topics on:

• Beer spoilage organisms that are deliberately used in niche beer styles.
• How bacteria are broadly classified by Gram stain reaction.
• Gram positive beer spoiling bacteria, Lactobacillus and Pediococcus, their occurrence in brewing and their metabolic effects in beer spoilage.

Figure: Lactobacillus

Figure: Pediococcus

• The evolutionary metabolic systems that hop resistant Gram positive bacteria use against iso-α-acids.

Figure: Model of hop resistance in Gram positive bacteria carrying the hor A gene

• The Gram negative bacteria involved in beer spoilage considering the relative threats of the aerobic and anaerobic groups, and why the anaerobic bacteria pose a new threat to breweries.
• The specific Genera and species involved in brewery contamination focusing on the origins, morphology, metabolism and tolerance within the brewing environment. Genera to be included are:
  • Acetobacter
  • Acetomonas
  • Zymomonas
  • Enterobacteriaceae
  • Obesumbacterium
  • Pectinatus
  • Megasphaera
• Wild yeasts including Saccharomyces and non-Saccharomyces species, including their metabolic products as beer off flavours.

Figure: Brettanomyces yeast

Lesson three

In the third lesson, we will learn about detection and control of contaminating microorganisms, including topics on:

• Aseptic sampling techniques from liquids solids and gases.
• Ways to concentrate samples for easier detection.

Figure: 250 mL Membrane filtration apparatus

• Optical microscopy and staining to enhance visualisation.
• Liquid and solid media and how they are used in the detection of aerobic and anaerobic microorganisms.
• Selective media and how these are tailored to grow and enrich the microorganisms described:
  • Lactic acid bacteria (LAB)
  • Acetic acid bacteria
  • Megasphaera and Pectinatus
  • Enterobacteriaceae
  • Zymomonas
  • Wild yeast
  • Brewing yeast
• Rapid methods of detection falling into the three categories
  • Physical tests:
    • Conductivity
    • Turbidimetry
    • Flow cytometry
    • Micro colonies

Figure: Micro colony automatic detection

• Biochemical tests:
  • API
  • DEFT
  • ATP
  • ELISA
  • GC

Figure: Principles of ELISA

• Molecular tests:
  • Hybridisation
  • Karyotyping
  • PCR

Figure: Principle of FISH