Salvaging yeast from a comercial keg?

[plumber_bob]

I'm new to harvesting yeast. I ferment in 1/2 barrel commercial kegs.

When I transfer to my cornies I get some sediment that I figure is yeast. And I get what I'm sure is yeast from each corny when I tap them.

The thing is, I find that in each case a bunch is left in all three kegs.

Were is the best place to harvest from? And how much starter to get it ready for the next pitch?

How would I know if I have enough to pitch after I do a starter?

pb

 

[mtnagel]

You can harvest yeast after primary fermentation from your primary container. In the simplest method, you literally scoop up some of the trub at the bottom and if you plan to brew within a week or so, you can just store it in a sanitized jar in the fridge and pitch that.

I learned a bunch about how many yeast cells are in trub in this thread. Basically, for most normal strength beers, you'd need about a cup of yeast cake to pitch into your next beer. That is just a gross approximation.

If you want to keep your yeast longer and reuse it later, you should wash it. More info here.

I made a calculator to tell you how many yeast cells you have in washed yeast. After you know how many yeast cells you have, you enter that into a yeast pitching rate calculator like yeastcalc.com and it will tell you what size starter you need for your beer.

What I've started doing and I think it's easier than washing yeast is harvesting from the starter. More details here. Basically you make a bigger starter than you need and pitch part of it into your next beer and keep a portion for use later.

There is a whole lot more info out there and I'm short for time, so I can write more later or you can ask more questions if you need more info.

 

[plumber_bob]

Thanks mtnagel,

Good info and I'll be checking into it more.

I was more concerned with methods for extracting the yeast from the bottom of a Sanke keg, (narrow mouth).
Siphon it? Dump into sanitized bucket.

What ever works for my 1/2bbl fermenter should work for my Cornies too.

I've built my stir plate and have a 2L flask. Stir bar, (2"), arrives today.
I'll be gearing up with starters, then on to harvesting in a few weeks, so I'll be picking through the info you just gave me.

Thanks

pb

 

[mtnagel]

Not sure how those kegs work, but I don't see why you couldn't siphon out your beer like normal and then pour it into another container to either save or start the washing process. I ferment in plastic buckets, so I siphon off most of the beer and then add some water like the link says and then transfer to another smaller container that is translucent, small and easy to pour from.

Just an FYI about the stir bars. I'm not sure what size your magnet is you are using, but I originally thought I needed a big stir bar, but it turns out the smaller one worked better because my magnet was smaller (it's a hard drive magnet). Basically you want to match the size of the stir bar to the size of the magnet for best results and so the stir bar doesn't fly off the stir plate.

 

[plumber_bob]

Thanks, after reading that article I think I'm going to try and wash my yeast and see how it goes. Might buy a siphon if I can't dump properly. We'll see how that goes.

Just an FYI about the stir bars. I'm not sure what size your magnet is you are using, but I originally thought I needed a big stir bar, but it turns out the smaller one worked better because my magnet was smaller (it's a hard drive magnet). Basically you want to match the size of the stir bar to the size of the magnet for best results and so the stir bar doesn't fly off the stir plate.

I ordered a 2" stir bar. I'm using a HD magnet too. It might be a tad shorter than 2" but should be close,... I hope. I'll know more when the UPS guy finally shows up.

My luck is that's too long and I'll bust my flask!
Thanks for the heads up, as now I'll do my testing in a plastic tub until I know more.:rockin:

pb --- Always waiting

 

[mtnagel]

I think the risk of breaking is low. I'm more concerned with having it reliably stirring when I'm not there or sleeping. If you set it up to stir and are depending on it stirring to build up your yeast count and you go to bed and it throws the stir bar shortly after, then you won't build as much yeast. Since I moved to erlenmeyer flasks with flat bottoms and a shorter stir bar (maybe 1"), mine never get thrown. Made two starters last night that were still stirring this morning.

 

[plumber_bob]

I'm using a 2L Erlenmeyer flask, and I measured the HD magnet, 1.5". So I'll probably be re-ordering to get a 1".

UPS still ain't here,... Damnit!

pb

 

[mtnagel]

It sounds like you might be okay. Definitely try it out before buying a new one.

 

[plumber_bob]

Oh, I will. If UPS ever gets here! LOL

I gotta go to be in bed in 1:45 so I'll be ready for work tonight. He'll show up 15 min. before that, I think he is messin' with me!

pb

 

[plumber_bob]

Well it finally got here.
Got 50Lb of 2 row, a huge SS mash paddle, .02 Micron SS stone, and the stir bar.

The stir bar seems fine with no liquid in flask. But when I add 1L of water it won't even spin up before the bar flings off.

I have about a 1/3" to 1/2" gap tho, so that might be a factor too. I'll have to tinker on my next time off.

pb