White Labs Inc. Pure Yeast and Fermentation team members have been active in the American and worldwide craft brewing movements since the 1980s. The company, which has grown to include offices in California and Colorado, provides a wealth of services to not only brewers but also winemakers, distillers and others in the fermentation business. Yeast Guarantee: White Labs goal is to become the best yeast production company in the world. We guarantee that each White Labs Liquid Yeast culture supplied meets our strict quality control standards. These QC standards are outlined on the Certificate of Quality Assurance supplied with the yeast and can also be found on our website. The QC standards define our requirements for purity and viability. We want you to have the best fermentation every time. If not, please contact us and we will work with you to make it right. White Labs is not responsible for other ingredient costs, beer costs, labor, etc, but we stand behind our product and our promise to you is that each batch is rigorously tested before it is released to you.