Commercial yeast propagation is not just for massively large breweries anymore. Many small breweries, and even larger home brewers, are finding it much more cost effective to engage in commercial yeast propagation than to simply continue to buy yeast from a manufacturer.
So what is commercial yeast propagation, and what’s so great about it?
The first step to commercial yeast propagation is to understand what yeast is and the role it plays in brewing, winemaking, and baking – basically any food or drink that requires fermentation.
Yeast is a single celled eukaryotic living organism that has been around for millions of years, and it has one job, one function.
Present in virtually all environments, yeast is in a constant state of seeking sugar to consume.
When it does find sugar, it converts it to alcohol and carbon dioxide, along with hundreds of other micronutrients and natural byproducts.
This process, called fermentation, is what allows yeast to thrive on our planet, and fortunately, there is no shortage of fermentable sugar sources.
Yeast can reproduce sexually or asexually and with or without oxygen, but it prefers oxygen and asexual reproduction, or budding.
This is why for millennia brewers, bakers, and winemakers have merely had to prepare their sugary sources and leave them out in the open air.
Within a day, yeast will find it and begin fermenting.
As a bonus, yeast will lie dormant, fully healthy and ready for collection to repitch into your next batch of whatever delicious, fermented concoction you’ve got going.
Yeast Propagation Today
Today, brewers, vintners, and bakers are doing just that – collecting the yeast from a completed batch or simply attracting yeast to their kitchens to pitch and propagate.
This can be done at home or on a massive commercial scale, and in each instance, you are much better off collecting and harvesting your own yeast than continuing to buy it from a manufacturer who may fail to deliver goods on time or fail to deliver on guarantees and promises.
Advantages to Yeast Propagation
There are many advantages to commercial yeast propagation, all of which have to do with providing a consistent product to your clientele.
The more consistent your product, the more loyal your clientele, which means the more word of mouth you will get for your product.
Word of mouth is hands down the most powerful form of advertising there is.
And you get it all with a consistent product.
When you propagate your own yeast, you have control over yeast cell viability and vitality, you can track a level of expectation across the fermentation process, and you can build your own yeast bank, marking which strains perform in which ways.
You also always have a reliable source of yeast all for an initial investment of equipment which will more than pay for itself.
Yeast Propagation Process
The yeast propagation process is the same in the beginning for all brewers, large and small.
The first step in yeast propagation is to collect or crop the remaining yeast from a previous batch.
To do this, you will simply drain your fermented beverage, also called racking, into the secondary vessel. Ideally, you have a conical shaped fermentation vessel, so your yeast and trub will settle on the bottom.
In terms of density, the trub, or solid matter that is not yeast, is heavier than yeast, so it will settle on the bottom of the cone. You can release your trub, which is darker in color, until you get to the yeast.
Then, you can collect your yeast, which typically lies in the center.
Finally, release the top layer, which is mostly slurry and remaining beer.
Rinse or Wash
Next, you’ll rinse the yeast.
Many larger breweries and wineries will also acid wash their yeast, but this step is largely unnecessary as the fermentation process will kill off any unwanted bacteria, and the acid wash process is a chemical one that will kill off a lot of your perfectly healthy yeast and lower your yeast viability.
A rinse is plenty, which simply involves adding your yeast to a container with filtered water, swirling it around, and then allowing it to settle.
After about a day, you will be able to crop the yeast, removing the white yeast from any remaining trub and slurry as you did above.
You can repeat this process as many times as you want with no fear of damaging your yeast.
Finally, you will either pitch your yeast into your next batch of wort or must or you can begin to propagate it.
Commercial Yeast Propagation
Yeast propagation merely means growing your yeast biomass from a small amount to a much larger amount.
You can do this by providing your yeast with enough sugar and oxygen to keep growing, but not enough to create alcohol.
You can of course do this by hand, by the process is labor intensive, requires exact temperature control, and you must stay on top of the propagation process.
At a commercial level, brewers will simply invest in a propagation tank which does all of this for you.
In a propagation tank, you pitch your small amount of yeast into the tank, add a liter of wort, and the cycle begins.
On the left side you will have a tank that is growing your yeast in wort at a cool 68 degrees Fahrenheit; on the right side, you will have a tank with much hotter, sterile wort, ready to feed your cooler wort as it gets hungrier.
This exchange continues, with temperature control, and fresh wort and oxygen introduction, until you reach your preferred amount of yeast, at which point you can pitch it into your next batch.
The added bonus of this process is that you can do it with multiple strains of yeast and keep an ongoing, consistent round of products available for your growing loyal fanbase.
Yeast activity monitoring is essential for optimizing the process of yeast harvesting and repitching! If you’re interested in finding out how you can use our technology to control fermentation and monitor your yeast, save work hours and improve the cost-efficiency of your business, drop us a line at email@example.com or check out the product pages (for beer or wine):
- Oculyze BB 2.0 (Better Brewing) Yeast Cell Counter App + Hardware
- Oculyze FW (Fermentation Wine) Yeast Cell Counter App + Hardware
Also, you can now get access to a fully functional demo account to test our Web App. Completely free of charge and with no commitment to purchase.