Our Quality Control Process

Our quality control program is very rigorous and designed to ensure that you get exactly the yeast you ordered and nothing else. Using qPCR, we achieve world-class sensitivity detecting contaminant organisms in our yeast slurries. 

Our Quality Control Program:

- Agar Plating at three points in the production process (starter, propagation, harvested yeast) using WLN, LCSM, and MRS media. 
- qPCR testing for Hop Resistant Bacteria, Brettanomyces, and Diastaticus.
- Test fermentation of harvested yeast in real wort.

QC Specs for product categories: 

Quality control specifications for Saccharomyces yeasts:
- Appearance on WLN agar matches with strain library
- Less than 1 / 10^7 CFU on MRS agar (anaerobic and aerobic incubation)
- Less than 1 / 10^7 CFU on LCSM agar (for yeasts known to be LCSM negative)
- No detection via qPCR for Hop Resistant Bacteria, Brettanomyces, and Diastaticus (cycle threshold = 35 corresponding to 10-50 cells/mL)

Quality control specifications for Brettanomyces and alternative yeasts:
- Appearance on WLN agar matches with strain library
- Less than 1 / 10^7 CFU bacteria on MRS agar (aerobic incubation)

Quality control specifications for Lactobacillus and Pediococcus bacteria:
- Appearance on WLN agar matches with strain library
- Appearance on MRS agar matches with strain library
- Less than 1/10^8 CFU yeast on WLN agar

Example Quality Control and Packaging Report (COA): 
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