Quality Control

We take pride in providing our customers with a consistent product every order, every time.  For more than a decade, our trusted partnerships have been built throughout the brewing community by an uncompromising commitment to quality, consistency and product transparency.  As a part of our commitment, Imperial Yeast employs a rigorous comprehensive quality control program, from the receipt of raw materials through the shipping of cultures, ensuring all cultures meet or exceed quality specifications and performance expectations. Below is an overview of our quality control (QC) program.  For more detailed product specifications, or questions regarding our QC program, please take a look at  our Technical Data Sheets or contact techsupport@imperialyeast.com. 

Raw Materials

Incoming raw materials move through compliance and suitability approval prior to release for use in media production.  Third party analysis and internal testing confirm established internal specifications have been met.  The handling of raw materials is compliant with Imperial HACCP and Allergen Control plans, as well as Kosher and Organic certification standards.  In addition, processed plant water is validated for compliance to microbiological specifications.

Processing

Strict processing parameters ensure every batch of propagation media meets internal standardized specifications.  The cleaning and sanitation of propagators and equipment are validated at multiple steps throughout the process.  Each stage of media processing is run through several physical checks confirming specifications are within accepted ranges.  Additionally, microbiological analysis is performed on processed media confirming the absence of spoilage organisms.  Propagations are monitored  throughout confirming physical and kinetic standards.

Finished Goods

All finished goods pass a comprehensive quality analysis before packaging and shipment.  Cell size, cell and colony morphology, growth on selective and differential media and real time PCR analysis are used in concert to validate conformity to internal standardized specifications and the absence of spoilage organisms.  Cell count and fluorescent viability assessments are performed using a Nexcelom Cellometer ensuring each package receives 1.29 billion viable cells per milliliter, every time.  All ingredients and processes for each lot are recorded and tracked internally, from order placement to fulfillment, for thorough accountability and traceability.

Finished Goods Specifications

  • Cell count 
      • Standard packaging - 1.29 X 109 viable cells/ml
  • Viability 
  • Cell Size (Mean Diameter) Strain Dependant - Consistent with Strain Ave
  • Cell Morphology Strain Dependant - Consistent with Strain Ave
  • Colony Morphology - Plating on differential media (WLN)
      • Consistent with the original mother culture
      • Single morphology
  • Plating on selective media for detection of spoilage organisms (UBA, LCSM)
      • UBA - Aerobic and anaerobic: Less than 1 CFU per 1 X 108 culture cells
      • LCSM - Aerobic 
        • Non STA1+ strains: Less than 1 CFU per 1 X 108 culture cells
        • STA1+ strains: Positive growth CFU dependent on strain
  • Real Time PCR for negative detection of spoilage organisms
      • Negative results (non-STA1+ strains)
        • Brettanomyces
        • Saccharomyces cerevisiae var. diastaticus 
        • Lactobacillus sp.
        • Pediococcus sp.
        • Hop resistant bacteria
      • Positive results (STA1+ strains)
        • Saccharomyces cerevisiae var. diastaticus