Author Topic: transferring onto trub and saving yeast  (Read 6433 times)

Offline keithshead

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transferring onto trub and saving yeast
« on: October 25, 2011, 11:57:02 PM »
Hi, got a couple of questions about yeast.

Firstly I am brewing an IPA at the weekend (estimated 1.065 OG) and am planning on transferring the cooled wort straight from my brew pot onto the trub left over from a blonde honey ale fermented with Wyeast London ESB. Now, I am expecting the fermentation to really kick off here and finish in just a couple of days. But is it possible that this may be classed as over pitching. And if so could i expect some off flavours in my finished beer?

Secondly, I would really like to make this yeast my house strain. What is the best way for me to store and re-use this yeast? I am aware of yeast washing but have read some negative comments about it. Could I save some of the trub in a 375ml bottle, cap it and put it in the fridge? Would the yeast begin feasting on the trub and.. err... mutate or something?


Offline pcollins

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Re: transferring onto trub and saving yeast
« Reply #1 on: October 26, 2011, 05:28:32 AM »
You'll likely get several conflicting responses on this one...

At a basic level, you're fine. I've pitched on a used yeast cake several times and it's just fine. Yes, it will take off like gangbusters so be ready with a blow off tube if you don't normally use one. Yes, it is over pitching but there isn't much that will come of that. Keep your temps under control and you should be fine.

I did an experiment once with a 10g batch of Pils that I brew. I pitched 5g of it on fresh yeast and 5g on a gelled yeast cake with all the trub and everything. Both came out fine with only a slight flavour difference that I would attribute to the trub left over in the carboy. It was not offensive at all, just different from the one pitched with fresh yeast. In a side by side comparison at a brew club meeting most people actually preferred the pils pitched on the gelled yeast cake with trub. Go figure.

I would go ahead and proceed with washing and storing. I don't know what negatives you've read about the washing and storing but I would say that anecdotally there are more negatives with pitching on a used yeast cake than washing and storing. If you're carefull with process and sanitation then the washing/storage route would be your best bet. I've also done that but for the amount of time it takes vs the results of pitching on a yeast cake I prefer the latter. 

Offline Beer_Tigger

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Re: transferring onto trub and saving yeast
« Reply #2 on: October 26, 2011, 06:41:06 AM »
I agree with the above comments as well.

I always make sure to progress thru complexity when using the yeast cake in the primary.  What I mean is, start with a simple English Ale, then pour on a Brown, then finally a Porter all one after the other on the same yeast.  As each beer is put on the yeast, the trub starts to pick up the flavor profile of the beer.  Adding a little bit of Brown ale flavor to a porter doesn't seem to affect the Porter.  However, the reverse is not a good idea.  For example, I would not do an IPA and then try dumping a simple Blonde onto that yeast/trub.  The flavor would be really screwed up.

I've done this many times, but only upto three beers.  I only have room for 4 in my kegerator anyway.  This works really well for lager yeast because it's such a big starter.

With a little planning, and careful sanitation, you can save some $ on yeast this way.  (Are all homebrewers as cheap as I am?)

I also store yeast in agar in test tubes for use upto a few years later.
"Let's see if this here beer will help me to stop procrastinating." - my cousin


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Re: transferring onto trub and saving yeast
« Reply #3 on: October 26, 2011, 08:17:29 AM »
The cleanest safest way I have found to harvest yeast will result in no contamination and near 100% Viability. Basically its a closed system.

First you need to brew a new batch with the yeast of choice. When the beer has reached High Krausen you want to skim the bubbles off the top. You can do this in a bucket fermentor and spoon but you will have a high risk of infection. Or you can use a carboy, a carboy cap, growler, 2 short rigid clear tubing (like a racking cane) a siphon tube and a double hole bung that fits the growler and an airlock.

What you want to do is sanitize everything first. Then put the carboy cap on with one of the rigid tubes in it. Run the siphon tube from the end of the rigid tube to the other rigid tube. Stick this one down inside the 2 hole bung and into the growler. You want it to sit about and inch or 2 from the bottom of the growler. Then put the airlock on the 2 hole bung in the growler. Now take the cane that is in the carboy cap and bring it slowly into the foam. Plug the other enfd of the carboy cap. Now what is going to happen is the force of the co2 is going to push the foam out and down into the airlocked growler. You can then suck up as much foam as you think you will need. Put a cap on the growler when your done a refrigerate until you need to use it. Your limited to harvesting ale yeast on this because lager yeast is bottom fermenting.

Works great with little risk of infection if everything is sanitized.

Now try to use the same yeast over and over for few brew sessions. Try to brew the same recipe over and over with it and it will lock that yeast into that recipe. Around 4 generations you get the best batch ever. After 6-7 batches throw it out and start over.

Offline keithshead

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Re: transferring onto trub and saving yeast
« Reply #4 on: October 26, 2011, 01:49:44 PM »
Thanks everyone. Lots of help there. I'll continue at the weekend as planned and also give yeast washing a go.

Offline dharalson

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Re: transferring onto trub and saving yeast
« Reply #5 on: October 27, 2011, 06:48:09 AM »
Just to add my penny's worth.
To store the yeast for any length of time.  (What a length of time is, is a very debatable question, I would use 2-4 weeks at the limit for short term)  So to store the yeast you really want to remove as much of the "food" as possible.  You don't want the yeast to continue to multiple, because they will mutate.  If you do store the yeast, make sure it can gass off, because it will continue to "work" even at pretty cold temperatures. 

Based on my readings and discussion with local microbrew masters, all breweries reuse their yeast on the order to 10+ recycles and the best beer comes from the 3rd+ recycle.  Apparently the yeast gets better at their job as they get used to a particular beer recipe.  Go figure.  Personally I don't brew often enough and I change styles everytime, so I have been culturing yeast on slants from yeast I have stored in sterile water.