Mastering Yeast Capture: A Guide To Brewing Success

If you want to capture yeast from beer, you will need to collect it from your fermenter depending on the type of yeast and your fermenting equipment. If you have a plastic fermenter that is easily accessible from the top, you can skim yeast off the surface of the beer during active primary fermentation. If you are fermenting your ale in a carboy or other vessel that is not accessible from the top, you will need to wait until primary fermentation is complete to harvest your yeast.

Yeast capture methods

There are two ways you can capture yeast: from the air or from some fruit, flowers, or other pieces of plant.

If you are using ale yeast and have a plastic fermenter that is easily accessible from the top, you can skim some yeast off the surface of the beer during active primary fermentation. You can also wait for the primary fermentation to subside and rinse some of the trub layer away with sterile water before collecting a sample of yeast. Then deposit the harvested yeast into a sanitized container, attach a loose-fitting lid or airlock and place it in the refrigerator.

If you are fermenting your ale in a carboy or other vessel that is not easily accessible from the top, you will need to wait until primary fermentation is complete to harvest your yeast. In this case, rack the ale into a secondary fermenter soon after primary fermentation begins to subside and harvest the sedimented yeast from your primary fermenter.

You can also capture yeast from the air by covering jars with cheesecloth and keeping them in place by screwing on the jar lids or tightening with a rubber band. Place the jars overnight outside in a herb or vegetable garden, under a fruit tree or even in your beer cave. Any place with good airflow, vibrant vegetation and free of curious woodland creatures will work fine.

You can also capture yeast from fruit, flowers, or other pieces of plant. Pitch that into a 1.5l starter wort of the same gravity. At this stage, you should have enough cells for a brew with an OG 1.060.

Use a fermenter

If you have a fermenter that is easily accessed from the top and are using ale yeast, simply skim some yeast off of the surface of the beer during active primary fermentation. An alternative method would be to wait for the primary fermentation to subside and rinse some of the trub layer away with sterile water before collecting a sample of yeast. Then deposit the harvested yeast into a sanitized container, attach a loose fitting lid or airlock and place it in the refrigerator.

If you are fermenting your ale in a carboy or other vessel that is not readily accessible from the top, you will need to wait until primary fermentation is complete to harvest your yeast. In this case, rack the ale into a secondary fermenter soon after primary fermentation begins to subside and harvest the sedimented yeast from your primary fermenter.

Wild yeast tends to have a particular character and doesn’t ferment as clean as some commercial yeasts. Some beers rely on this unique character to create their particular flavor profile. Wild yeast can be captured from the air, or from some fruit, flowers, or other piece of plant.

To capture yeast from the air, place jars outside in a herb or vegetable garden, under a fruit tree or even in your beer cave. Any place with good air flow, vibrant vegetation and free of curious woodland creatures will work fine. Cover with cheese cloth (to prevent insects from crashing your yeast party) and keep in place by screwing on the jar lids or tightening with a rubber band. Remove the cheese cloth the next day.

You can also capture yeast from fruit. Pitch that into a 1.5l starter wort of the same gravity. At this stage you should have enough cells for a brew with an OG 1.060.

Capture from air

There are two ways you can capture yeast: from the air, or from some fruit, flowers, or other pieces of plant. Here, I will cover the first one.

You won't need much to capture some yeast. You will need jars, cheese cloth, and petri dishes. Cover the jars with cheese cloth (to prevent insects from crashing your yeast party) and keep it in place by screwing on the jar lids or tightening with a rubber band. Place the jars overnight outside, in a herb or vegetable garden, under a fruit tree or even in your beer cave. Any place with good air flow, vibrant vegetation and free of curious woodland creatures will work fine. Please don’t put near a septic tank, an alley or other potentially contaminated place (it’s disgusting, and probably not safe).

The next day, bring in any cooled jars left outside. Remove the cheese cloth. Then, pitch that into a 1.5l starter wort of the same gravity. At this stage, you should have enough cells for a brew with an OG 1.060. Unfortunately, this involves some guess work as unless you have the required tools to count how many cells your capture has, we’re just estimating the cell count. But hey, it’s free yeast, so just try again.

You can isolate the yeast cells in your capture, but that is outside of the scope of the article. For this process, you will require a few more items like petri dishes, wire loops, alcohol burners, agar etc.

Capture from fruit, flowers or plants

To capture yeast from fruit, flowers or plants, you will need a few more items like petri dishes, wire loops, alcohol burners, agar etc.

You can capture yeast from the air, or from some fruit, flowers, or other piece of plant. The process will be the same for the latter.

You can capture yeast from the air by covering a jar with cheese cloth and keeping it in place by screwing on the jar lids or tightening with a rubber band. Place the jars overnight outside, in a herb or vegetable garden, under a fruit tree or even in your beer cave. Any place with good air flow, vibrant vegetation and free of curious woodland creatures will work fine.

If you have a fermenter that is easily accessed from the top (such as a plastic bucket) and are using ale yeast, simply skim some yeast off of the surface of the beer during active primary fermentation. An alternative method would be to wait for the primary fermentation to subside and rinse some of the trub layer away with sterile water before collecting a sample of yeast. Then deposit the harvested yeast into a sanitized container, attach a loose fitting lid or airlock and place it in the refrigerator.

Use a jar

If you want to capture yeast from beer, you can do so by using a jar. Here's how:

First, you'll need to collect yeast from your fermenter. This will depend on the type of yeast you want to collect and the equipment you have. If you have a plastic fermenter that is easily accessible from the top and are using ale yeast, you can skim some yeast off the surface of the beer during active primary fermentation. If you are fermenting your ale in a carboy or another vessel that is not easily accessible from the top, you will need to wait until primary fermentation is complete to harvest your yeast.

Once you have collected the yeast, you can use a jar to store it. Cover the jar with cheesecloth to prevent insects from getting in and keep it in place with a rubber band or by screwing on the jar lid. Place the jar outside in a well-ventilated area with vibrant vegetation and good airflow. You can also place it under a fruit tree or in a beer cave.

The next day, bring in any cooled jars left outside and remove the cheesecloth. You can now pitch the yeast into a 1.5l starter wort of the same gravity. This will give you enough cells for a brew with an OG less than 1.060.

Remember, this process involves some guesswork as you estimate the cell count unless you have the required tools to count the cells. However, it's free yeast, so you can always try again!

Frequently asked questions