Yeast and Cultures

A rigorous quality control and quality assurance program utilizes both traditional methods and modern innovations to guarantee culture purity and single morphology down to the threshold of detection. Cultures, ingredients, and equipment are analyzed and held to strict specifications throughout the entire propagation process. Complete QA/QC analysis on every finished product means our strict specifications are always met before your order ships.

Analyses include:

• Plating on general and selective media for detection of viable yeast and bacteria contaminants
• Colony morphology on differential agar
• Cell morphology with phase contrast microscope
• qPCR confirmation of commercial yeast species (S. cerevisiae, S. pastorianus, S. cer. var. diastaticus, and Brettanomyces)
• qPCR screening for the detection of STA1+ yeast and common brewhouse contaminants

Base strains of mixed culture products complete QA/QC analyses prior to blending, to guarantee the integrity of morphology and purity of each incorporated strain.

Wyeast provides the most precisely packaged yeast slurry to guarantee consistent, reliable fermentations in your brewhouse and barrel aging program. No range or minimum – we prepare our Saccharomyces strains at exactly 1.2 billion viable cells per milliliter and Brettanomyces strains at 750 million viable cells per milliteter with advanced cellometer & validation processes. This results in > 99.9% viability for your target pitch rate – delivering the most accurate cells per mL per Plato calculations for reproducible fermentations.

All mixed culture products are standardized to these specifications prior to blending, so that even your most creative fermentations are reliably reproducible – no matter the barrel or year.

Every strain is initiated from our ultra-low temperature archive in order to maintain genomic stability, ensuring the culture maintains consistent fermentation kinetics, flavor profiles, and flocculation characteristics.

Brettanomyces cultures are propagated using a nutrient-rich, premium malt extract based medium under specialized oxygenation schedules and temperature parameters for specific growth and cell health requirements. Extended propagation schedules also allow for high cell density. These processes ensures the yeast are always conditioned to an environment similar to brewers wort and fermentation conditions.

Bacteria cultures are propagated on premium malt based medias with genus-specific nutrient additions, with anaerobic environment and elevated temperature conditions utilized throughout the entire propagation. Lactic acid production and pH decrease are monitored for the duration of growth.

Wyeast ships directly from our facility in Hood River, Oregon USA to yours, guaranteeing the freshness and integrity of every order. One production facility means consistency and reliability, batch after batch.