Yeast Harvesting

[nickgoupil]

Good day all!

Currently I have 5 gallons of an Chocolate Oatmeal Stout which has been in primary for 11 days using a Wyeast 1056 for that. I also have a Pacific Jade IPA which has been in primary for 4 days using 2 packs of re hydrated US-05. I’m planning on learning the whole harvesting yeast to use on future beers. I’ve been reading some information and watching videos on youtube for properly cleaning the yeast. I have two questions after all of this.

1. Once I separate the trub and the suspended yeast into small pint sized mason jars I will let the yeast completely settle to the bottom of the mason jar(over the course of a few days). When creating a starter, do I pour the remaining liquid left in those mason jars down to the settled yeast and create a new starter with that before pitching?

2. I know you’re never supposed or there is no need to make a starter with dry yeast but re hydrating gives you the most amount of cells. That being said can I harvest US-05 and re-use it for a few generations of beer after primary fermentation?

Thank you very much for any feedback!

[birdstop]

[quote=“NickGoupil”]Good day all!

Currently I have 5 gallons of an Chocolate Oatmeal Stout which has been in primary for 11 days using a Wyeast 1056 for that. I also have a Pacific Jade IPA which has been in primary for 4 days using 2 packs of re hydrated US-05. I’m planning on learning the whole harvesting yeast to use on future beers. I’ve been reading some information and watching videos on youtube for properly cleaning the yeast. I have two questions after all of this.

1. Once I separate the trub and the suspended yeast into small pint sized mason jars I will let the yeast completely settle to the bottom of the mason jar(over the course of a few days). When creating a starter, do I pour the remaining liquid left in those mason jars down to the settled yeast and create a new starter with that before pitching?

2. I know you’re never supposed or there is no need to make a starter with dry yeast but re hydrating gives you the most amount of cells. That being said can I harvest US-05 and re-use it for a few generations of beer after primary fermentation?

Thank you very much for any feedback![/quote]

1. Yes, but you need/“should” have an idea of how much “viable” yeast you have in the jar before you make a starter.

2. Yes and same as above.

Remember, when re-pitching yeast always try to pitch from lighter beers to darker or light to light and dark to dark and from lower gravity beers to higher gravity beers. This is just a “general” rule and is not without exceptions.

Happy re-purposing yeast.

[mattnaik]

@Birdstop

1. Yes, but you need/“should” have an idea of how much “viable” yeast you have in the jar before you make a starter.

Interesting. How do you do this without knowing how many cells were produced by the initial fermentation?

[s_scoggin]

you can’t know your viability unless you have a microscope, hemocytometer, and some methelyn blue. I probably spelled those wrong, but whatever.

making a starter will ensure you have viable cells. you can use the yeast calculator for “slurry” on mrmalty.com to give you a good estimate on how much yeast you need.

When you’re settling the yeast in your mason jars, you can poor the liquid on top down the drain, and only use the thick yeast slurry for your starter. If the yeast is fairly new, you probably don’t need to make a starter with the yeast slurry, it should have plenty of cells. If it’s older, I’d either buy new yeast, or make a starter.

[birdstop]

There are about 4.5 billion yeast cells in 1 milliliter of yeast solids (solids with no excess liquid).

This is assuming you rinsed your yeast very well from an active fermentation and what you have in the bottom of your vessel is all yeast. We can then assume that if this yeast is fairly fresh, one or two weeks old, that the yeast is 80% viable. This would give you about 3.6 billion yeast cells in 1 milliliter of your yeast solids. About 28 milliliters of this yeast solids should give you the same approximate amout of yeast cells found in a White Labs vial or in a Wyeast smack pack. Then make your starter in whatever manor you would need to to grow your yeast count to the pitching rate needed for what you are brewing.