Making a starter from harvested yeast

[Josephryanevan]

Hey folks,
I've got a quick question about making yeast starters. I've got some yeast that I have harvested and washed from a previous batch. It's all settled to the bottom and there's quite a bit, probably 6-7 ounces of solid yeast at the bottom.

My question is, how much of this should I take out to make a 1 liter starter?
Also, what's the best method for getting it out and stain sanitary? Swirl and pour? Beer thief? Syringe?

Thanks,
Joe

 

[RedlegEd]

Hey folks,
I've got a quick question about making yeast starters. I've got some yeast that I have harvested and washed from a previous batch. It's all settled to the bottom and there's quite a bit, probably 6-7 ounces of solid yeast at the bottom.

My question is, how much of this should I take out to make a 1 liter starter?
Also, what's the best method for getting it out and stain sanitary? Swirl and pour? Beer thief? Syringe?

Thanks,
Joe

Joe,
Last question first. I don't like sticking anything into a yeast slurry. IMO, it's always better to pour from the container. Now on to your other question. It depends how long you've had the yeast in the fridge, and the total amount of slurry (yeast and the "beer" on top.) Let's say you have a 16oz mason jar 2/3 full and it's been no more than four weeks, then I'd recommend swirling the jar to get the slurry all mixed up. Sanitize the jar lid before removing, then pour about 4-6 oz into a sanitized measuring cup to build your starter. If your yeast is still good and viable, you should see your starter turn to a beautiful coffee with cream color in ~12-18 hours. Hope this helps. Ed

ETA: Picture

 

[Dcpcooks]

Hey folks,

I've got a quick question about making yeast starters. I've got some yeast that I have harvested and washed from a previous batch. It's all settled to the bottom and there's quite a bit, probably 6-7 ounces of solid yeast at the bottom.



My question is, how much of this should I take out to make a 1 liter starter?

Also, what's the best method for getting it out and stain sanitary? Swirl and pour? Beer thief? Syringe?



Thanks,

Joe

Age is the question as that impacts viability. You'll lose some yeast as it ages. I've seen estimates as high as 3-5% a week but that may be on the high side.
So if it's fresh half is probably a good starting point. If it's old then you'll want more. I don't know what size jar you've collected in so I can't tell you how much to use. Have you used the old white labs vials in the past? You can use that as a reference point to help determine what you have as far as volume. Yeast without a slurry weighs 8 grams per 100 billion cells. You still need to account for water weight. Water weighs 1 gram per mm. So a relatively dense slurry would require roughly 90 grams of slurry for a five gallon batch. So you can get a clean and sanitized mason jar and pour off your slurry into the jar on a scale to get you in the ball park. I'd err on the high side unless your yeast is less than a week old.


To transfer it I would spray the whole container with star San. You can also flame the edges and sides with a light pass of a propane torch. Try to keep it quick and make sure you don't do it in a drafty place.

Most times starters are for growing the population. In your case your looking to see signs of viability and health more then growth. So I'd make a nice 1-2l starter of 1.040 wort and spin it 3-4 days before you plan to use it. I like to crash it after so I can pour off the spent wort.

 

[flars]

Hey folks,
I've got a quick question about making yeast starters. I've got some yeast that I have harvested and washed from a previous batch. It's all settled to the bottom and there's quite a bit, probably 6-7 ounces of solid yeast at the bottom.

Six ounces is about 177 milliliters. I estimate 2 to 4 billion cells per milliliter depending upon which yeast I harvested. You would probably be safe estimating 2 billion cells per ml. A picture would help. How much viable yeast depends upon how old the yeast is.
I usually use the date the yeast began the active fermentation of the brew the yeast was harvested from. Since the yeast was rinsed deduct 5% viability as a safety factor. Harvested yeast is much healthier and stores longer when it is stored under beer.


My question is, how much of this should I take out to make a 1 liter starter?
I use this pitch rate/viability calculator to estimate how much of the yeast to use for the next brew.
http://www.brewunited.com/yeast_calculator.php

I won't use all of the harvested yeast for a new fermentation even if the calculator estimates I have enough cells. I'll use about 100 ml in a starter to propagate fresh cells.

Also, what's the best method for getting it out and stain sanitary? Swirl and pour? Beer thief? Syringe?

Best method to take the yeast out is swirl the contents and then use a percentage of the total to pour out the number of cells to use in the starter.

Thanks,
Joe

This is good reading on harvesting yeast.
https://www.homebrewtalk.com/showthread.php?t=579350
I hope some of this is helpful.

 

[Josephryanevan]

Thanks a lot for the help. This is good stuff.

So my yeast is 2 months old. Quite a bit older than all of the things y'all were mentioning. I would guess then that I want to assume that a lot of the cells have given up the ghost. If 3-5% per week is the die off rate, I've lost a lot. Potentially almost half.

 

[flars]

Thanks a lot for the help. This is good stuff.

So my yeast is 2 months old. Quite a bit older than all of the things y'all were mentioning. I would guess then that I want to assume that a lot of the cells have given up the ghost. If 3-5% per week is the die off rate, I've lost a lot. Potentially almost half.

What does the Brew United calculator estimate for viability?

 

[Josephryanevan]

Thanks for the help folks. The yeast calculator is a big help.