Craft brewing is filled with passionate brewers dedicated to perfecting their recipes and delighting patrons with the latest beer styles. Most beer enthusiasts marvel at the hops, malt, and other flavoring agents in beer, yet yeast is the silent hero behind the scenes. Yeast plays a pivotal role in the flavor and aroma of craft beer. Often overshadowed by other ingredients, the choice and treatment of yeast can drastically shape a beer’s character. Yeast is a delicate creature. Meticulous handling, propagation, and management of this miraculous microorganism significantly impacts a brewery’s operational costs and beer quality.
Yeast plays a pivotal role in the brewing process. It converts the sugars present in the malt into alcohol and carbon dioxide. This fermentation process defines the beer’s alcohol content, mouthfeel, and a significant portion of its flavor profile. The health and vitality of the yeast strain used can drastically alter the end product.
Improper yeast handling leads to contamination, off-flavors, and an inconsistent beer. For a craft brewery, where the uniqueness and consistency of each batch are paramount, this spells disaster. This is where the yeast brink and propagators are vital components of the brewing process.
A yeast brink or propagating vessel offers craft breweries numerous advantages and is fundamental to optimizing the fermentation process. It ensures a consistent supply of healthy and viable yeast cells, that is crucial for achieving desired flavor profiles and ensures batch-to-batch uniformity. This consistency leads to higher quality brews and fewer batch failures. By cultivating their own yeast strains, breweries can experiment and create unique flavor profiles. This helps distinguish the brewery’s products in a competitive market. Additionally, a brink or propagator can result in cost savings. Breweries can reduce or eliminate the need to frequently purchase new yeast cultures. As we all have seen, there has been a huge rise in cost and freight charges for yeast in the last couple years. Moreover, re-pitching yeast from a well-maintained brink or propagator reduces the risk of contamination that might come from external sources.
Traditionally, breweries purchased yeast for every batch. With the advent of yeast brinks and propagators, breweries now harvest, grow, and pitch their own yeast. This not only offers cost savings, but also ensures a higher level of consistency and control over the yeast’s health and long-term vitality.
Breweries can order smaller quantities of yeast to propagate prior to inoculating a larger volume of wort. Propagations are a cost-effective yeast management method for brewers who want to employ multiple yeast strains or are brewing too infrequently to re-pitch harvested yeast. To be cost effective, brewers must have the proper tools and quality control measures. They must ensure clean yeast slurry at the correct density is achieved for a proper pitch rate and a healthy fermentation. Cell counting, viability testing, and microbiological testing are no longer only for large breweries. These are critical, accessible procedures that can be incorporated into every brewery’s propagation routine.
Both yeast brinks and yeast propagators play important roles in a brewery, but they serve distinct purposes and are used at different stages of the brewing process.
Purpose: A yeast brink is essentially a storage vessel, designed to hold yeast in between fermentations.
Features: Typically, it is a stainless-steel container that maintains a cool temperature to keep the yeast in a dormant state.
Usage: After yeast is harvested from a fermenter, it is stored in the brink until it’s needed for the next fermentation. By using a brink, brewers ensure they have a ready supply of healthy, viable yeast for pitching.
Advantages: The use of a yeast brink leads to cost savings since brewers re-pitch yeast from previous batches, rather than buying new yeast each time. It allows brewers to manage yeast more effectively, ensuring its health and viability.
Purpose: A yeast propagator is designed to actively grow and multiply yeast.
Features: It is an environment where yeast is fed a nutrient-rich medium (often wort) to promote growth. It often has systems in place for mixing, aeration, and temperature control to create the ideal conditions for yeast propagation.
Usage: When a brewery needs to increase its yeast supply, whether to amplify a small amount of yeast purchased or to cultivate a particular strain, they use a propagator.
Advantages: A propagator allows brewers to maintain yeast health and vitality, ensuring consistent fermentation profiles. It also offers a way to multiply yeast stocks without going through a full fermentation cycle.
While both the yeast brink and yeast propagator are associated with managing and handling yeast in a brewery, the brink is about storage and maintenance, and the propagator is focused on active growth and multiplication of yeast cells.
To properly size a yeast propagation vessel, brewers first determine the desired yeast pitching rate for their specific beer style. Once this rate is established, the brewer can calculate the total number of yeast cells required for a given batch size and wort gravity. Considering the propagation efficiency and the expected final concentration of yeast cells in the propagator, the brewer then determines the volume of the propagation vessel. It’s crucial to ensure that the propagator is sized adequately to accommodate not just the volume of the yeast slurry but also the growth medium and the space required for aeration and stirring mechanisms. Proper vessel sizing ensures optimal yeast health, growth, and fermentation performance.
The volume of yeast to pitch from a propagator or slurry often depends on the concentration of viable yeast cells in the suspension. Brewers aim for a specific number of yeast cells per milliliter of wort, and the volume of yeast slurry needed to achieve this target is influenced by the density of yeast cells within the slurry.
On average, here are some general guidelines:
For Ales: A common pitching rate for ales is around 750,000 to 1 million cells per mL per Plato. If the yeast slurry has a concentration of roughly 1 billion cells per mL, the need is:
1 to 2 liters of yeast slurry per barrel (bbl) of wort.
For Lagers: Lagers typically require a higher pitching rate, usually around 1.5 to 2 million cells per mL per Plato. Again, using a yeast slurry concentration of 1 billion cells per mL as an example, the need is:
2 to 4 liters of yeast slurry per barrel (bbl) of wort.
These are general guidelines. The actual volume of yeast slurry needed will depend on the specific concentration of viable yeast cells in the propagator or slurry, the original gravity of the wort, and the specific strain of yeast. Most professional craft brewers perform cell counts to determine the exact concentration of their yeast slurries, allowing them to pitch the optimal volume for each batch of beer.
The volume of yeast a brewery requires is influenced by the diversity of yeast strains maintained, as well as the brewing and production frequency. At MARKS, our experienced sales team is equipped to guide you in determining the appropriate size and number of vessels that would best suit your yeast handling demands. While we provide standard vessel sizes of 3, 5, 7, 10, and 15bbl, we also specialize in custom designs and sizes.
Recognizing the importance of yeast management in the craft beer industry, MARKS has dedicated itself to providing custom solutions tailored to each brewery’s unique needs. Our custom yeast brinks and propagators are USA sourced and fabricated. They are crafted with precision, ensuring that the yeast is maintained in optimum conditions throughout its lifecycle.
MARKS doesn’t stop at merely offering tank solutions. Our yeast systems can be equipped with advanced controls and automation. This means brewers can set up specific “recipes” for yeast propagation, ensuring that parameters like temperature, oxygen levels, and mixing rates are consistently maintained.
One of the standout features of our automation system is remote monitoring. In an era where being physically present at the brewery 24/7 is not feasible, having the capability to monitor and adjust the system remotely is invaluable. It ensures that any potential issues can be identified and managed in real-time, preserving the yeast’s health and ultimately the quality of the beer being brewed.
In the evolving world of craft brewing, the emphasis is on innovation, quality, and consistency. By investing in efficient yeast management solutions like yeast brinks and propagators, breweries not only save on operational costs but also ensure that the beer they produce meets the high standards their beer followers expect. The beer we love is as much a product of the passionate brewer as it is of the tiny yeast cells that work tirelessly behind the scenes. Cheers to them!