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General Category => Yeast and Fermentation => Topic started by: rbclay on March 20, 2011, 09:12:17 PM

Title: starter with old slurry
Post by: rbclay on March 20, 2011, 09:12:17 PM
Several questions here...
 
First time I've harvested yeast to use at a later date. I usually just pitch right on the cake. I have a 800ml (24oz) jar that has settled into 300ml of thick yeast with about 300ml beer that was left on the slurry on top. The yeast was harvested 12/28. It's  3rd gen 1056. I plan to use it in a cream ale OG 1054.
 
Mr.Malty calculator says I need 600ml slurry based on the date. He says it's only 10% viable. That amount is just slurry- not slurry in a starter, correct? So if I put the slurry I have in an SG 1035 1.5L starter on a stir plate I should be pretty close, yes? I probably won't double the volume so it may be an underpitch, but it should still be enough, yes?
 
I'm also making a second batch of the same cream ale and using WLP001. That is the exactly the same as 1056, yes? The only reason I'm buying WL is because I got a coupon. Not that there is anything wrong with WL. I have just always been a Wyeast guy. I will make a starter with that tube.
 
I'm looking at this as a yeast experiment. Theoretically the beers come out exactly the same. We shall see. And it is also kind of an experiment with the stir plate. First time using it. And it's homemade. I figure I'm really putting it to the test throwing 300ml thick slurry in 1.5L starter.
 
Thoughts?
Title: Re: starter with old slurry
Post by: hopfenundmalz on March 20, 2011, 09:43:37 PM
If you start with WY-1056 and WLP-001, and pitch equal amounts of starter slurry into wort split from a batch, the results will be very similar, but not identical.  

A friend who is a very accomplished brewer did this a few years back.  The WY-1056 was a little "rounder" in the flavor.  

US-05 was also done in this test.  It was different still, and finished a little more dry, almost tart.  1056 and 001 were closer together than US-05 was to either of those.

Someone else with more knowledge can answer the rest of your questions.
Title: Re: starter with old slurry
Post by: rbclay on March 20, 2011, 09:46:37 PM
Thanks. On second thought I will use 1056 as the other yeast. I don't really want to add another variable. I will use the WL coupon for something else.
Title: Re: starter with old slurry
Post by: weithman5 on March 20, 2011, 09:50:22 PM
i don't know abouit the flavor profiles, but i think if you build up your slurry no worry. i have a nearly 1 year old mason jar with similar amount of white labs 820 or 830 (the san fran lager yeast what ever the number) it is about a year old and i am going to build up a starter tomorro, just to see if it will go.  i think it will be fine.
Title: Re: starter with old slurry
Post by: a10t2 on March 20, 2011, 09:52:44 PM
I wouldn't pitch nearly 600 mL of slurry that old. I don't know why the MrMalty calculator assumes so much viability loss for slurry - at 25%/month it would be about 40% viable. Either way, that's a ton of dead yeast to be putting into a beer. I'd put at most 100 mL of slurry (30-120 billion cells, depending on viability) into a starter and let MrMalty tell you how large the starter needs to be.
Title: Re: starter with old slurry
Post by: rbclay on March 22, 2011, 09:46:09 PM
Quote
I'd put at most 100 mL of slurry (30-120 billion cells, depending on viability) into a starter and let MrMalty tell you how large the starter needs to be.

Sorry- I don't follow. How do I put in the amount of slurry in Mr. Malty calculator? For 5G of OG 1054 wort it says I need 189 billion cells. Based on the date it says thats 532ml of slurry. I follow what you are saying about not having that much loss of viablilty in 3 months. But I only have 300ml of slurry. The other 300ml is beer. If I put 100ml of this old slurry in a 1.5L starter of SG 1035 and put in on a stir plate, what kind of growth can I expect?
Title: Re: starter with old slurry
Post by: rbclay on March 22, 2011, 09:52:39 PM
Another question- will the yeast be too shocked with about a 10-15degree difference in temp? I'm letting the slurry jar come up to room temp. It's at 62. I want to chill the starter to 75 and pitch. Good idea? Like a full batch of wort, I figure the thermal mass of the starter will keep it at 75ish if it starts fermenting soon enough. I also added a pinch of nutrient and 1 min. of O2.
Title: Re: starter with old slurry
Post by: denny on March 22, 2011, 09:56:05 PM
Another question- will the yeast be too shocked with about a 10-15degree difference in temp? I'm letting the slurry jar come up to room temp. It's at 62. I want to chill the starter to 75 and pitch. Good idea? Like a full batch of wort, I figure the thermal mass of the starter will keep it at 75ish if it starts fermenting soon enough. I also added a pinch of nutrient and 1 min. of O2.

Actually, you can get better performance by not letting it warm up first.  Colder yeast into warmer wort is a good thing.  I generally pull mine out of the fridge and pitch it right away.
Title: Re: starter with old slurry
Post by: rbclay on March 22, 2011, 10:11:55 PM
I think that answesr another question about starters that has benn bugging me. Everyone talks about crash cooling and decanting. But they never mention letting the yeast warm up before pitching. Now I know why...
Title: Re: starter with old slurry
Post by: a10t2 on March 22, 2011, 10:12:56 PM
Sorry- I don't follow. How do I put in the amount of slurry in Mr. Malty calculator?

The viability field is really just the number of cells (in billions). So make your estimate at how many cells you have, put that in the viability field, and let the calculator pretend it's a smack pack.
Title: Re: starter with old slurry
Post by: rbclay on March 23, 2011, 05:27:52 PM
Next question- the starter looks good. I used about 100ml (1/2C.) in a SG 1035 1.5L starter. It's been on the stir plate 19 hours. It is past high krausen. It is 72F. Is it OK to pitch into a 62F OG 1054 wort? I need to top off the wort anyway, so I was going to pitch the whole thing.
Title: Re: starter with old slurry
Post by: Hokerer on March 23, 2011, 05:55:39 PM
Next question- the starter looks good. I used about 100ml (1/2C.) in a SG 1035 1.5L starter. It's been on the stir plate 19 hours. It is past high krausen. It is 72F. Is it OK to pitch into a 62F OG 1054 wort? I need to top off the wort anyway, so I was going to pitch the whole thing.

You'd probably be better off sticking it in the fridge, decanting the spent wort, pitching that and then topping up with water.  That spent wort, especially since it's from a stir-plated starter, is going to be nasty and oxidized and you probably don't want to be adding ever just the liter and a half of that.

Plus, if you refrigerate, you'll be able to follow the "pitch yeast colder than the wort" thingy.
Title: Re: starter with old slurry
Post by: rbclay on March 23, 2011, 06:04:10 PM
So cold crashing/decanting shouldn't take long right? I don't want to shock it too much. I'm going to stick it in the fridge, check it in an hour. I'm looking for clarity and about 55-60F I reckon. It's at 76F now. Thanks...
Title: Re: starter with old slurry
Post by: rbclay on March 24, 2011, 02:05:15 AM
So it's 8 hours later. Starter is cold crashed. I'm oxygenating the wort, decanting the starter and pitching the thick slurry. Gotta empty the flask to get another starter going!!
Title: Re: starter with old slurry
Post by: Hokerer on March 24, 2011, 02:48:01 PM
So it's 8 hours later. Starter is cold crashed. I'm oxygenating the wort, decanting the starter and pitching the thick slurry. Gotta empty the flask to get another starter going!!

Sounds like a good excuse to get a second flask  ;D
Title: Re: starter with old slurry
Post by: rbclay on March 24, 2011, 03:06:33 PM
Pretty sure this yeast didn't really enjoy the roller coaster ride yesterday. It is starting to ferment, but definitely longer lag than usual. I am really curious to see what the end result will be. I am brewing the control batch tonight. Fresh smack pack in a starter pitched at high krausen.

Of course I would like more flasks! Couple weeks ago I broke my 1L flask. Replaced it with a more useful 2L. And picked up a 500ml one. Perfect for priming solutions. Need another 2L. And might as well build another stir plate, right? First one unded up running me about $40. I know I can do one for under $20 now.
Title: Re: starter with old slurry
Post by: gmac on March 24, 2011, 03:08:01 PM
Anyway you could post your directions for building a stir plate?   
Title: Re: starter with old slurry
Post by: denny on March 24, 2011, 03:16:03 PM
How much longer lag?  I have to admit, I don't worry much about lag time unless it's excessive...like 3 days.
Title: Re: starter with old slurry
Post by: rbclay on March 24, 2011, 03:43:35 PM
I'm not much of an airlock bubble counter, I just look for the active bubbling to start. I am doing this one in a 6.5G bucket that has a good sealing lid. It hasn't started actively bubbling and it has been 13 hours since pitch. I did pop the airlock out earlier this morning to peak in. I did see foam, so it has started. Just not real vigorous. I'm just being picky! I'm sure it's all good...

I don't usually use a blow off tube with worts that are about OG 1050 or less. (5G in a 6.5G bucket). But now that I will be doing stir plated starters I will have my blow off assembly at the ready!
Title: Re: starter with old slurry
Post by: Hokerer on March 24, 2011, 03:53:51 PM
Of course I would like more flasks! Couple weeks ago I broke my 1L flask. Replaced it with a more useful 2L. And picked up a 500ml one. Perfect for priming solutions. Need another 2L. And might as well build another stir plate, right? First one unded up running me about $40. I know I can do one for under $20 now.

There ya go.  I've got two 2L and six 500ml flasks and yes, I'm seriously contemplating building myself a second stirplate.

Still haven't found a good enough price on a 4L or 5L flask yet though :(
Title: Re: starter with old slurry
Post by: tygo on March 24, 2011, 05:25:07 PM

Still haven't found a good enough price on a 4L or 5L flask yet though :(

Morebeer has them for $40.  Not a great price but it is part of their free shipping program which is pretty good for a glass item.