Question - Creating 2nd Gen Yeast Supply

[jybingbrew]

I've read through a lot of threads on washing yeast from the carboy, creating yeast banks, etc -- but didn't find a lot of info on what I'd like to do.

I'd like to take some yeast vials I have in the fridge and build up a collection of 2nd generation yeast to be used in starters later on -- I don't want to wash yeast from a batch right now, and don't want to freeze. I want to keep it fairly simple as I get used to the whole propogating yeast idea.

My thought is to step up a "starter" from 1L to 3L by adding a Liter each day for 3 days, and then crash cool the "starter". I'd decant off the top, and try to leave myself with just the yeast slurry on the bottom.

After that, add enough boiled/cooled water to get the total volume up to the # of 1/2 pint mason jars I think I can split the yeast population into (maybe 6?). I'd then jar that slurry into mason jars that I've sterlized with a pressure cooker and refrigerate.

Does this process sound reasonable to take 1 vial, and get about 6-ish samples that I can use to make starters for future beers?

Seemed like a decent mix of yeast washing, storing, etc to get used to the various aspects of the process without making it too complicated.

Thoughts appreciated. Thanks!

 

[TimT]

I would do the starter in 1L then crash, decant and add 3L+. Adding a bit at a time will not get you the growth you want. For yeast growth 4-10 times is the amount used usually not a bit each day.

 

[jybingbrew]

Thanks -- That makes sense.

Everything else I describe sound reasonable?

Appreciate the input.

 

[NordeastBrewer77]

Thanks -- That makes sense.

Everything else I describe sound reasonable?

Appreciate the input.

sure does. i've done pretty much that, make a starter with fresh yeast, cold crash when done and thrown the slurry in mason jars for later use. i'd suggest when you plan to use one of the jars of slurry, make another starter to bring up the yeast to population.

 

[jybingbrew]

Thanks - Just curious since you have done this before... how long have you been able to successfully use this refrigerated yeast, assuming of course you make a starter with it?

Seems general consensus on here is at least a year, with a starter?

 

[NordeastBrewer77]

if you're making a starter, i'd say months, at least. i've never kept yeast around for longer, but i know a lot of guys do. just always make a starter to check viability and grow new yeast.

 

[jybingbrew]

Thanks, I think I'll plan to split enough to be around for 6 months and see how it goes. If it's still viable at that point, I'll do it again and try for 9 months or a year (or look into freezing). Just didn't want to create too much and waste the storage space for yeast that had no chance of being viable.

 

[cram]

jybingbrew: your method looks good but +1 on the idea that it's better to add some wort and let the yeast eat all the sugar (+/- three days) and then decant and add more volume than before (as opposed to your idea of adding a little bit as you go). Good sanitizing practices should allow it to keep in the fridge for awhile (six months easy, maybe a year) but always make a starter first, and taste the "beer" made from it before pitching, just to be sure.

A stir plate helps a ton. I fabbed one with an old computer power supply box and hard-drive magnets; all that I had to buy was a stir bar and a rheostat because (I had some toggle switches on hand already). They're super easy to make and I'm sure you could ask around and source most of the parts for free. I stocked up on parts from the tech guy at my work. I have a ton of 12V wall warts if anyone needs one...

Harvesting 2nd generation yeast is the way to go. I just harvested dregs from a Duvel bottle and let it go on the stir plate for a week, with one step up mid-week, and I filled two mason jars with a lot of slurry. You can build a good collection just from the dregs of bottle conditioned beers.

As for keeping a strain going, I think it's easier to make a big starter before brewing and pull off some of the starter and save that for your next go 'round, as opposed to washing/harvesting from a primary. Good luck!

 

[jybingbrew]

Thanks! Forgot to mention that I do have a stir plate. Built one over the weekend in anticipation of trying to do this. Posted pics over at the "Show us your ..." thread.

https://www.homebrewtalk.com/f51/show-us-your-diy-stir-plate-228400/index11.html

I am jealous that you have a stockpile of 12V chargers... I've burned through all of mine between a few keezer and temp control builds and the stir plate build.

Anybody happen to have a good calculator to figure out how many cells you are able to make when stepping up a starter? I've tried to reverse engineer Mr. Malty but haven't quite figured it out yet -- seems like somebody might have already solved that issue before.

Figured I would need to approximate how much yeast is in each of my mason jars right?

 

[thisoneguy]

This is a great calculator from Sulli, another HBT member. If I remember right, the Mr. Malty page gives some guidelines about estimating how much yeast is in a slurry based on how dense the slurry is. I don't have the link handy right now, sorry.

 

[jybingbrew]

That looks like a great calculator for this, thanks for sharing. Surprised I haven't run into that before.