yeast harvesting

[Aarong2008]

I have a few yeast related questions. I want to get into harvesting yeast from my 5 gallon batches and I have watched many videos on how to do so. Usually, they split up the slurry into 4 or 5 smaller mason jars and I was curious how to figure out how much slurry you would need for a starter for a 5 gallon batch? Is one of the mason jars enough? I haven't seen anyone explain that.

My next question is about bottle harvesting yeast. I have also read and watched videos on how to do so with the step up method, but I haven't found a clear answer when you have enough slurry for 5 gallons.

Thanks.

 

[d3track]

Use one of the pitch rate calculators. You have to do some rough estimating, but it will get you close to the correct pitch rate.

 

[Calder]

The easy way: Use slurry within a week and use roughly a quarter (to a third) of the total slurry from the batch for the next beer. No washing, no starter, just keep in fridge until needed.

I have used slurry up to 2 months old with no issues. I usually bump up he pitch to half the slurry if it is that long.

I work off the fact that at the end of fermentation a beer will end up with roughly 6X the 'correct' pitch rate (from Yeast, Zainasheff & White). Factor in some yeast has died, some is still in suspension, and so I estimate roughly 4x gets harvested. That's my rationale for using a quarter of the slurry. I think it is as accurate (or more accurate) than using a calculator for slurry.


The hard way: use a starter, figure out what quantity is solids, how much increase you get, etc. Even washing yeast is a pain.

 

[flars]

Some very good information here.
https://www.homebrewtalk.com/showthread.php?t=519995
I will have 350 to 400 ml of yeast in one quart jar from a 5 gallon batch. I have strained the hops from the wort during the pour into the fermentor. I've been estimating 2 billion cells per ml when I reuse the yeast.

 

[MagicMatt]

I like to harvest from my starters instead of messing around with the yeast in the bottom of the carboy. I just overbuild my starters by 100 billion cells, and then pour off the appropriate amount of slurry (usually I'm building a starter to get to around 250B cells to pitch, plus the 100B extra = 350B total, so I generally save about 1/3 of the starter).

I then let the saved portion sit in the fridge for a week and then decant and store in 50mL test tubes with equal parts yeast slurry and 20% glycerol solution, and then freeze indefinitely.

This essentially gives me a fresh smack pack's worth of yeast to use later, and I should never have to buy that strain again.

 

[coolharry]

I'm with Matt, harvesting from a starter is my go to now. I use homebrewdads calculator and have had great success overbuilding by about 100 billion cells. I let the starter ferment out and pour off about 400-500 ml into a mason jar, cold crash it, decant the liquid and then store it in soda bottle preforms (similar to the old white labs tubes) for later use.

 

[Calder]

I like to harvest from my starters instead of messing around with the yeast in the bottom of the carboy. I just overbuild my starters by 100 billion cells.

I then let the saved portion sit in the fridge for a week and then decant and store in 50mL test tubes with equal parts yeast slurry and 20% glycerol solution, and then freeze indefinitely.

I'm with Matt, harvesting from a starter is my go to now.

I do that for every starter, to save for some for use time way in the future, but for re-use for consecutive batches, it is wayyyyyyy less effort to just pull some slurry and re-pitch. All you need to do is sanitize the collection jar.

 

[Natdavis777]

Once in the jars, the yeast settles into a thick slurry. Most pint mason jars have an mL marker on the side. Sources on the internet state thick slurry can contain anywhere from 1-4 billion cells per mL. Wyeast states that it is 1.2 billion cells per mL, which is what I go by for conservative reasons. That way, if my cell count per mL is more, then I overpitch (not an issue with homebrewers) than underpitch.

Even so, after washing, I tend to collect ~60mL thick yeast in each pint mason jar. This equates to 72bil cells, which is equivalent to a roughly 1 month old wyeast smackpack.

I have two yeast starters going currently with third generation 1056 that is 1 month old (60mL/each) that both took off <12 hrs (better than some smackpacks) on a stirplate for a brew tomorrow. I honestly prefer harvested yeast over bought yeast.