More dumb yeast questions

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whovous

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So, I've been trying to make the transition from pitching a new package of dry yeast into every new brew to the whole pitch liquid yeast, then save the slurry, make a starter and repitch it in the next brew routine. I feel like I am getting parts of the routine down, but I dunno about the rest.

Anyway, I am up to about a fourth generation of Gigayeast Vermont IPA. This batch was taken from a NE IPA brewed with Citra/Mosaic/Galaxy - basically as described by Braufessor in his popular NE IPA thread. I decided to do a full liter starter this time, but it seemed to completely overwhelm my mini stir plate, so I poured off a little bit of it. Even then, I got ZERO vortex and just a little bit of rattling noise from my stirbar. I decided to let it go, and hope for the best. The rattling appears to have been sufficient agitation to get the yeast going again. Agreed?

Sorry about the sideways pix. Question about the first picture. It shows a large greenish layer and a thinner whitish layer of krausen. Why the difference? I assume the color comes from the hops in the prior brew, but why the split?

Questions about the second picture. 1) Just what do I want to pitch? Do I pour off the beer and pitch both the green and white layers, or what? If I need to separate them, how do I do that? 2) How much do I want to pitch? I am targeting four gallons to the fermenter, an OG of 1.067 and an ABV of 7.5% assuming 70% efficiency. 3) Do I need to do anything more than just bring it back to room temp, decant, and pitch? I know about oxygenating.

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After.jpg
 

bobeer

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You need to wash your yeast to get rid of all the hop trub. There are many videos on how to wash yeast. My personal favorite is Don O's guest appearance on Chop and Brew. http://chopandbrew.com/episodes/chop-brew-episode-04-washing-yeast-with-don-o/

Basically you get boiled and cooled water and throw it on top of the yeast cake in your carboy. Swirl it around and get everything all mixed up. Then let it sit for about 10-15 minutes. All the dead yeast, hop junk, and other trub will fall to the bottom and you'll be left with the good yeast floating in suspension. Decant that into a smaller vessel, like a 1 gallon glass jug, add more clean purified water, mix it up, and let it sit again for a little longer. Then decant again into mason jars or whatever you're going to store your yeast in, label yeast type, generation number, and date, and put in your fridge.
That's pretty much it. Now, I've made starters when using washed yeast but lately I've just been dumping it right out of the fridge into the wort. I just did this with a 1.103 stout and it attenuated down to 1.019 so I don't think a starter is always 100% needed. There was a few days of lag time but it wasn't a big deal since I have already have a couple beers on tap that I need to get through.

I hope this helps!
 
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whovous

whovous

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Thanks. Now, assuming the green layer is trub and the white layer is yeast, why did the trub wind up on top in the pictured starter? This is why I get confused about yeast!
 

beergolf

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Try this next time. Make a big starter from a fresh pack of yeast. Pour some off into a jar to save for the next batch, and pitch the rest into your brew. Next time do the same thing. Use the jar of yeast from the last starter to make another big starter, and pour off a jar to save......

This way the yeast is much cleaner ( no hop debris), not stressed from a higher gravity brew, etc. and you can just keep going with the yeast from one pack for a long time.

Much better way to do it.
 
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whovous

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I am targeting 7.5% and contemplating adding dextrose if I miss my target by much. 70'ish IBU's and a new hop bill very similar to the old hop bill.

Now, does that look like a lot of yeast, as in quite a bit more than I need for 4 gallons, or should I not worry my pretty little head about that? Overpitching seems a lot safer than underpitching.
 

brew703

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this is normally how I do it:
https://www.homebrewtalk.com/showthread.php?t=568046&page=87

Sometimes I do brew and use an entire liquid yeast pack with no starter and no dry hop and just harvest the slurry. I do not harvest any that has been dry hopped.

lately when I need to use harvested slurry, I take out a jar, warm to room temp. When my wort is about 30 min from finishing with the boil, I take about 500 ML of wort, cool to pitch temps and take the harvested yeast and dump in the flask and then on the stir plate for a few hours until wort is cooled to pitch temps.
Brulosophy outlined this process in a exbeeriment.
 
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whovous

whovous

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this is normally how I do it:
https://www.homebrewtalk.com/showthread.php?t=568046&page=87

Sometimes I do brew and use an entire liquid yeast pack with no starter and no dry hop and just harvest the slurry. I do not harvest any that has been dry hopped.

lately when I need to use harvested slurry, I take out a jar, warm to room temp. When my wort is about 30 min from finishing with the boil, I take about 500 ML of wort, cool to pitch temps and take the harvested yeast and dump in the flask and then on the stir plate for a few hours until wort is cooled to pitch temps.
Brulosophy outlined this process in a exbeeriment.
I like the sound of this. Can you give me a link to the specific exbeeriment? I think I am going to do this regardless. I'd like to read up on it but I could not find it with a quick Google search.
 

IslandLizard

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As @beergolf said, yeast ranching (saving some from a starter) is preferred over harvesting yeast, especially when it's trubby or high gravity and more so after dry hopping. Yeah, you could try to wash or rinse the yeast, but there are some major drawbacks and only few advantages.

If you find yourself using the same yeast often, make a large, overbuilt, 2 liter starter from a fresh smack pack, pure pitch pack, or vial, save some out for your next batch, and pitch the rest.

I always use a yeast calculator, like Brewunited or yeastcalculator to give me a decent perspective on cell count. The 1 liter flask you're using is a bit small as you'll see. I only use the 1 liter ones for step up from small yeast quantities.
 

IslandLizard

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You mentioned a rattling stir bar and no vortex. That means it really isn't spinning (being thrown) or your stir bar is too small. 1" is a good size but also about the minimum. 1.25-1.5" could work better but depends on the stir plate. Something to do with the size of the plate's magnet or spacing if it's using 2 magnets.

The shape of bottom of the flask also comes into play. The flatter the better. But if the magnets(s) in the plate are strong enough, about any flask or jar will do, even those 1/2 gallon or gallon jugs.
 
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As @beergolf said, yeast ranching (saving some from a starter) is preferred over harvesting yeast, especially when it's trubby or high gravity and more so after dry hopping. Yeah, you could try to wash or rinse the yeast, but there are some major drawbacks and only few advantages.

If you find yourself using the same yeast often, make a large, overbuilt, 2 liter starter from a fresh smack pack, pure pitch pack, or vial, save some out for your next batch, and pitch the rest.

I always use a yeast calculator, like Brewunited or yeastcalculator to give me a decent perspective on cell count. The 1 liter flask you're using is a bit small as you'll see. I only use the 1 liter ones for step up from small yeast quantities.
My yeast policies are definitely evolving. I got a "mini" stir plate and a 1 liter flask because I do fairly small batches, typically about three gallons. Today, for the first time, I will try to get a four gallon batch out of my six gallon pot.

Anyway, both a two liter flask and a Maelstrom stir plate are en route to me as I type this. No doubt my practice will continue to evolve. Right now, I like what I have read about the "viability starter" approach, and will use it for today's brew.
 
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You mentioned a rattling stir bar and no vortex. That means it really isn't spinning (being thrown) or your stir bar is too small. 1" is a good size but also about the minimum. 1.25-1.5" could work better but depends on the stir plate. Something to do with the size of the plate's magnet or spacing if it's using 2 magnets.

The shape of bottom of the flask also comes into play. The flatter the better. But if the magnets(s) in the plate are strong enough, about any flask or jar will do, even those 1/2 gallon or gallon jugs.
The whole result was pretty bizarre. My flask has a completely flat bottom, and I have never before had a problem getting a vortex from it. I guess my batch sizes have always been smaller, however. But even though the stir bar seemed to be rattling more than spinning, I got a quite large krausen as you can see from the photos. It looks like you really don't need much in the way of agitation for a starter. Still, the new gear en route (which includes a longer stir bar, FWIW) should give me all the vortex I could ever want.
 

IslandLizard

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The excess of krausen is a tell tale of regular fermentation, not necessarily yeast propagation. With a good spinning bean and a foam stopper/foil cover, the yeast is exposed to adequate O2 levels, needed for maximum growth. In your case it may have hit middle ground.

Also, the amount of trub could be a cause of the stir bar jumping, or not seeing a vortex.

I'm quite sure you'll like your new toys!
 

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whovous

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The excess of krausen is a tell tale of regular fermentation, not necessarily yeast propagation. With a good spinning bean and a foam stopper/foil cover, the yeast is exposed to adequate O2 levels, needed for maximum growth. In your case it may have hit middle ground.
Isn't that a lot of yeast in the second photo?
 

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Isn't that a lot of yeast in the second photo?
Yes, it is a fair lot. But it's not pure yeast, there's a significant amount of trub mixed in. How much? hard to tell, say 50%? You be the judge. How much (mixed) slurry did you pitch into that starter? You should subtract that from the total to calculate gain. The difference is your new yeast!

Have you plugged in some real life based values into those yeast calcs to see what gives you the most growth? For example pitching 200 billion (viable) cells into a 1 liter starter? Then try 100, 50, 20. Look at the growth rates for each and the final (estimated) count. Repeat for a 2 l starter. It took me a few years and lots of reading to get some understanding how yeast behaves.

Look at the differences in final cell count a stirrer makes compared to intermittent "shaking." Swirling 4 times a day isn't going to cut it.

I typically make 1.6-1.8 liter starters using one of those calcs, and the results are confirming.

Your new stirrer should plow through about anything. Your little one needs a little check to see why it doesn't vortex. Again, could be the thickness of the slurry.

Adding one drop of Fermcap-S to starter wort decreases the amount of foaming, reducing a lot of boil overs in the starter wort and foaming in the flask.
 
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whovous

whovous

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I've always considered myself real good at math, but my eyes still glaze over when it comes to counting yeast cells. I started reading Yeast, but haven't gotten very far with that, either. I keep it by my bed in hopes of osmosis, but so far no luck!

I do think I am headed in the right direction on the yeast learning curve, but the top of the curve continues to recede into the distance. Oh well, a year ago I wouldn't even consider using liquid yeast...
 
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