How Is Yeast Harvested?

, a microscopic fungus, is a vital ingredient in baking and . While commercial yeast is readily available, many people are interested in capturing wild yeast to add a unique flavor and character to their creations. In this article, we will explore how to capture wild yeast and harness its fermentation power.

To begin, gather some dried fruits of your choice. Raisins, apricots, or dates work well for this purpose. Place a handful of these dried fruits into a clean jar, ensuring that the jar is large enough to accommodate the fruits and some .

Next, fill the jar with filtered water, covering the dried fruits completely. Yeast thrives in a moist and carbohydrate-rich environment, so the water provides the ideal conditions for yeast to grow and multiply.

Once the jar is filled with water, seal it tightly with a lid or cover it with a piece of cloth secured with a rubber band. This step is crucial to prevent any unwanted contaminants from entering the jar while still allowing air to circulate.

Now, it's time to store the jar in a suitable location. Yeast is present in the air around us, and by placing the jar in an area with good air circulation, such as a kitchen counter or a windowsill, you increase the chances of capturing wild yeast. Allow the jar to sit undisturbed for a few days or up to a week.

During this time, you may notice some activity within the jar. Bubbles and froth formation are signs that yeast is actively fermenting. This means that you have successfully captured wild yeast.

To harness the power of the captured yeast, you can drain off the liquid from the jar and use it in your baking or brewing recipes. However, it is essential to remember that the captured wild yeast may not be as potent or predictable as commercial yeast. Therefore, it is recommended to use it in recipes that allow for a longer fermentation period, such as sourdough bread or homebrewed .

To propagate and maintain your wild yeast culture, you can mix two cups of flour (preferably unprocessed or without preservatives) and two cups of water in a glass or pottery bowl. Place a cloth over the top to allow air circulation and let it sit on your kitchen counter.

Over time, the wild yeast present in the air will find its way into the flour and water mixture, initiating fermentation. You can feed the culture regularly by discarding half of the mixture and adding fresh flour and water. This process helps maintain the yeast population and ensures its vitality.

Capturing wild yeast is an exciting and rewarding process. It allows you to experiment with unique flavors and create baked goods and beverages with a distinct character. By following the steps outlined in this article, you can successfully harvest wild yeast and embark on your fermentation journey. Happy capturing!

Yeast Harvested 1694335263

How Do You Grow And Harvest Yeast?

To grow and harvest yeast, there are several methods you can follow. Here is a step-by-step guide:

1. Prepare the yeast growth medium: Yeast needs a nutrient-rich environment to grow. You can create a growth medium by combining water, sugar, and some additional nutrients like yeast extract or extract. This mixture provides the necessary food for yeast to thrive.

2. Sterilize the growth medium: It's important to sterilize the growth medium to prevent the growth of unwanted bacteria or fungi. You can do this by heating the mixture to a temperature between 121-130°C (250-266°F), using a pressure cooker or autoclave. Allow the mixture to cool down before proceeding.

3. Inoculate the growth medium: Once the growth medium has cooled down, add a small amount of active yeast culture or a commercial yeast packet to the mixture. This will introduce the yeast cells into the growth medium.

4. Provide suitable conditions: Yeast requires specific conditions to grow effectively. Maintain a temperature between 25-30°C (77-86°F) and provide adequate aeration by either stirring the mixture gently or using an air pump with an air stone. Yeast also prefers a slightly acidic environment, so try to maintain a pH level around 4-6.

5. Monitor the growth: Over time, you will notice the yeast population increasing. It may appear as a cloudy suspension or foam on the surface of the growth medium. You can periodically sample the mixture to check the yeast cell density using a microscope or by measuring the optical density with a spectrophotometer.

6. Harvest the yeast: When the yeast population has reached its maximum density, it's time to harvest the yeast. You can do this by gently separating the yeast cells from the growth medium. One method is to refrigerate the mixture overnight, allowing the yeast to settle at the bottom. Carefully decant the liquid, leaving behind the yeast sediment. Another method is to use a centrifuge to separate the yeast cells from the liquid.

7. Store the harvested yeast: Once you have harvested the yeast, it's important to store it properly for future use. You can freeze the yeast in small portions or store it in a sterile container with some of the growth medium, refrigerating it at a temperature between 2-8°C (36-46°F). This will help maintain the viability of the yeast for an extended period.

By following these steps, you can successfully grow and harvest yeast for various applications, such as baking, brewing, or scientific research.


Yeast can be easily harvested by capturing wild yeast from the environment. One simple method is to place dried fruits, such as raisins, in a jar and fill it with filtered water. By sealing the jar and allowing it to sit, the yeast will thrive in the moist and carbohydrate-rich environment. After a few days, the water will start bubbling and frothing, indicating that wild yeast has been successfully captured.

Once the wild yeast has been harvested, it can be used for various purposes, such as making bread or brewing . To propagate the yeast, a mixture of flour and water can be left uncovered in a glass or pottery bowl on the kitchen counter. The yeast floating in the air will be attracted to this mixture and start growing and dividing. This process allows for the cultivation of large quantities of yeast for future use.

It is fascinating to think that yeast, a microorganism that has been used by humans for thousands of years, can be found all around us in the environment. By understanding how to capture and propagate wild yeast, we can harness its fermentation abilities to create delicious and nutritious foods and beverages. So, next time you want to bake a fresh loaf of bread or brew your own beer, consider capturing wild yeast and embarking on a journey of homemade fermentation.

Photo of author

Thomas Ashford

Thomas Ashford is a highly educated brewer with years of experience in the industry. He has a Bachelor Degree in Chemistry and a Master Degree in Brewing Science. He is also BJCP Certified Beer Judge. Tom has worked hard to become one of the most experienced brewers in the industry. He has experience monitoring brewhouse and cellaring operations, coordinating brewhouse projects, and optimizing brewery operations for maximum efficiency. He is also familiar mixology and an experienced sommelier. Tom is an expert organizer of beer festivals, wine tastings, and brewery tours.