Yeast Quality Control Explained: Why Your Supplier Matters
How To Compare Yeast Quality Control Specifications
Yeast can make or break your beer — but not all yeast is created equal. Cutting corners on quality control can leave you with contaminated batches, inconsistent results, or costly do-overs.
Why does one yeast supplier charge more than another? The answer lies in their quality control process. All that lab testing and validation is expensive, after all! Let’s dive into what separates high-quality yeast from the rest and how to ensure you’re getting the best.
Let’s start with an illustration. These three agar plates shown below are all real-world examples of testing identical amounts of yeast from commercial producers for the presence of lactic acid bacteria colonies (the white dots).
Which of the three would you rather pitch into your wort?
Probably the one on the right, unless you’re planning to make a sour beer.
Why is it important to compare yeast suppliers' quality control?
Brewers rely on yeast to deliver flavour, aroma, and fermentation consistency. But not all yeast suppliers prioritize quality control equally. A single contaminated or inconsistent batch of yeast can lead to off-flavours, poor attenuation, or even ruined beer.
Framed a different way, you should ask yourself which of these costs more:
- One failed batch (total costs including ingredients, labour, rent, energy, opportunity cost, reputation)
- Investing in premium yeast
Different QC standards—like thresholds for bacterial contamination or yeast viability—can explain why one yeast is more expensive than another. Yeast with higher QC standards minimizes risks, saves time, and ensures consistency, which is why brewers often invest in it.
At Escarpment Labs, we believe brewers deserve access to premium yeast with transparent quality control. By focusing on high QC standards, we ensure you can trust your yeast every time.
How do QC standards differ between yeast suppliers?
Different yeast suppliers use different frameworks to ensure quality. Some invest heavily in advanced testing methods like qPCR, while others rely on simpler tools. This impacts the levels of bacterial contamination, yeast viability, and performance reliability in their products.
How do I read a yeast spec sheet?
While we can’t speak to everyone’s spec sheets (Technical Data Sheet, Certificate of Analysis), we can offer the following pointers:
- Yeast contamination thresholds are usually stated in Colony Forming Units, which is more easily understood as “viable cells” that can form colonies on an agar plate.
- Most suppliers state the contamination thresholds as a certain number of CFU per cells of yeast, providing a clear and easy-to-understand ratio.
- The higher the ratio of Colony Forming Units to yeast, the higher the allowable contamination rate in the yeast product.
- Some dry yeast suppliers state the contamination thresholds as a value per gram, which requires further calculation to determine the actual contamination threshold claimed.
Here is an example of the section from Escarpment’s spec sheet:
Ideally, suppliers should list the actual testing methods and equipment used alongside the QC threshold.
Example: Comparing contaminant levels in different beer yeasts
By reviewing the Technical Data Sheets and Certificate of Analysis from various yeast suppliers, it is possible to survey the current state of the industry. The results show differences in accepted contamination levels. A graph comparing relative QC thresholds across suppliers demonstrates this:
The differences in yeast quality between suppliers aren’t just small - they’re exponential. For example, one supplier might allow up to 100,000 lactic acid bacteria cells per 10 million cells of yeast, while another sets their threshold at just 1 cell per 10 million yeast cells. That’s a 100,000-fold difference in sensitivity to contamination.
In general, most liquid yeast producers are aligned at a threshold of around 1 contaminant per 10 million yeast cells, with some suppliers slightly higher or lower than this threshold. There is much greater variability in the QC thresholds on the technical sheets for dry yeast products.
All of this matters because bacteria and wild yeast can grow exponentially during fermentation. A small contamination at the start can multiply into a big problem by the time your beer is finished, affecting flavour, aroma, and even shelf life. A high contamination rate will also add a lot of risk if the brewery plans to repitch the yeast.
When you choose yeast with stricter quality control, you’re not just buying “cleaner” yeast—you’re drastically reducing the risk of problems in your beer. It’s the difference between a batch you’re proud of and one that ends up down the drain.
What do we do at Escarpment Labs?
- Advanced QC Testing: We use state-of-the-art methods like qPCR and sensitive “old school” methods like agar plating to detect a broad spectrum of contaminants.
- Strict QC Thresholds: Every batch of yeast must meet rigorous standards for purity, viability, and performance before leaving our lab.
- Transparent Reports: We provide detailed QC data so you know exactly what you’re getting.
- Expertise Across Liquid and Dry Yeast: We offer both liquid (Escarpment Labs) and dry (LalBrew) yeast, ensuring premium quality for every brewing style.
- Commitment to Education: We help brewers understand what QC standards mean and why they matter when selecting yeast
How You Can Compare Yeast Suppliers
Here are some tips for evaluating yeast options:
- Request QC Reports: See if suppliers share their standards and results.
- Examine Contamination Thresholds: These are often confusing, so we have included guidance in this article.
- Check Viability Standards: Look for data on how suppliers ensure yeast is fresh and viable.
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Understand Yeast Pricing: Higher-cost yeast often comes with stricter QC and better reliability. Ultimately, it costs more to produce and test yeast with a higher purity, resulting in premium yeasts having a higher cost to the customer. However, premium yeasts reduce your risk and can be repitched to achieve cost savings.
What will you choose?
Quality control is the foundation of a reliable yeast supplier. Understanding the differences in QC standards can help you choose yeast that delivers consistency and peace of mind.
Want to learn more about yeast QC? Try these resources!
WHY SHOULD YOU TRUST OUR YEAST? QUALITY CONTROL AT ESCARPMENT LABS
