Do you need to wash yeast if you make a starter with origional vial of yeast to put in different jars for future batches.? I do 2.5 gallon batches,so how many jars can you get out of 1 vial/starter? And how big of a starter should I use?
For those of you who harvest from 5 gallon batches, use jars with marked measurements and follow this method exactly, filling 4 jars with slurry....
How many ml thick would you say your cake is after a few days in the fridge?
What's the longest anyone here has stored washed yeast and effectively used it. And of course with a starter.
jb3218 said:After a couple of days in my secondary, I notice what looks like yeast on the bottom. Is that indeed yeast or something else. Also, I thought that once the yeast cells ate the sugars, they were no any good. Is the yeast at the end of fermentation the extra cells that were not needed? Yeast washing looks interesting and I may try it in the near future so I'm trying to understand it better.
After a couple of days in my secondary, I notice what looks like yeast on the bottom. Is that indeed yeast or something else. Also, I thought that once the yeast cells ate the sugars, they were no any good. Is the yeast at the end of fermentation the extra cells that were not needed? Yeast washing looks interesting and I may try it in the near future so I'm trying to understand it better.
I have been washing and reusing my yeas for a couple of years now with this same technique with good success. However, I have just for the most part, been using .25gal starter wort to 1 pint jar of yeast wash per 6 gal regardless of the OG. My question is, (and I apologize if it was previously covered but I did try searching without finding any results to my liking), but lets say I just brewed a 6 gallon batch @ OG 1.057. How many of the pint jars of the washed yeast do you suggest and at what volume of starter wort do you suggest?
I have tried using Mr. Malty but I am not certain what the results mean due to the fact I am unsure how to enter the data correctly. I know, call me stupid...sometimes I just need it spelled out for me.
Thanks, any help would be greatly appreciated,
Jason
What's the longest anyone here has stored washed yeast and effectively used it. And of course with a starter.
In order to use Mr Malty or YeastCalc, you need to start by figuring out how many viable cells you have. Ideally, you'd count them directly... but few of us have the capacity to do this.
What I do is to start by figuring out how many mL of condensed slurry I have in the bottom of my pint jar. The easiest way to do this if it's a small amount is to set an identical jar next to it and add water until it's to the same level as the slurry, then pour out and weigh that water in grams---that's how many mL of slurry you've got.
The next question is how many cells were in there. To do this, you've got to figure out the density in cells/mL. Basing this on the book "Yeast" and the MrMalty documentation, if you have solid yeast, it's about 4.5 billion/mL, and about 1 billion/mL if it's a thin slurry. Mine are usually pretty solid, so I usually use something like 3 billion/mL as a guess. You've probably got 10-25% non-yeast mixed in also, so you ought to scale to account for that, but it's not really necessary given the other uncertainties in this process.
Ok, so you have X mL of slurry at Y billion cells/mL, so multiply the two numbers to get your cell estimate. Now you have to figure out the viability. You can get some idea by playing with the dates on the MrMalty calculator and watcing how its viability goes, but many people challenge the general validity of its model. I usually just assume it's between 50 and 100% and plan my starter steps so that I'll have an acceptable pitch rate at either extreme.
So, for example, on my recent rinsing, I had about 10 mL of compacted slurry, which is roughly 10 * 3 = 30 billion cells. I played around with yeast calc and came up with a 3 step starter that was right at the desired pitch rate for 15 billion cells (50% viability) and was about 15% high for 30 billion cells (100% viability). Using two or three steps will reduce your sensitivity to starting count somewhat. I think I used a 500 mL first step.
Hope that helps. It's not very precise, but I think it's about the best you can do short of counting cells.
This may have confused me more
So if I have a pint jar, and it's 1/4 full of thick yeast. That would be 118 ml. So that would be roughly 354 billion cells. So I would have to do a starter to triple this then it sounds like for a standar 5g batch?
So I wonder if throwing the whole pint(thick and thin), into a 2L starter would suffice for a 5g batch.
So if I have a pint jar, and it's 1/4 full of thick yeast. That would be 118 ml. So that would be roughly 354 billion cells. So I would have to do a starter to triple this then it sounds like for a standar 5g batch?
If you have 1% viability you'd needs a multi-step starter. It all depends on the age/viability of the yeast and how much other crap is in there.
If it's very low viability, there's also the issue that you probably won't get the results you expect from the strain. By the time a significant fraction of the yeast have died, the characteristics of the survivors will be selected for "can survive a long time in a pint jar in the fridge," not, "makes good beer."
Also, you'd probably want to do a starter and decant just to separate the live yeast from the dead so that you don't pitch a ton of dead yeast into your beer.
Ok. So I just had a question. I use a blowoff and a lot of the time I will end up with a layer of what looks like yeast that settles out in my bottle of blowoff starsan. Would this theoretically be usable? Or would you all suggest against it? Here is a picture for your viewing pleasure.
I'm not sure about either of those things. Especially the second, though. Dead yeast just serve as nutrients during the lag phase. In fact, a lot of people throw yeast in during the boil of high gravity brews to give yeast an extra boost.
Speaking of the book "Yeast," I really need to move it out of my Amazon wish list and into my cart. Does it recommend a rinsing approach similar to the one in this thread?
I'd also like to better understand what Jamil means by "slurry" on the 'Repitching from Slurry' tab on mrmalty.com. Anyone know if this is covered in the book? Based on his comments on Brew Strong, it seems like he does a less involved version of this thread's approach (i.e., a single rinse with less water), but I don't know if he considers that a "slurry" or something else.
It's widely recommended that you (e.g., the book "Yeast") not pitch yeast with < 90% viability. Selective pressure and general yeast health are among the reasons for this.
As for the latter, I realized last night that just decanting won't get rid of dead yeast, you'd need to do something else to manage that. As to whether it's a good idea, I don't think *pitching* intact, dead yeast is a good idea. Boiling it is different---that will denature proteins, etc, so it's more like adding nutrients. I don't know for certain that pitching dead yeast will cause problems, but I feel pretty confident saying it's not going to help you.
In order to use Mr Malty or YeastCalc, you need to start by figuring out how many viable cells you have. Ideally, you'd count them directly... but few of us have the capacity to do this.
Speaking of the book "Yeast," I really need to move it out of my Amazon wish list and into my cart. Does it recommend a rinsing approach similar to the one in this thread?
I'd also like to better understand what Jamil means by "slurry" on the 'Repitching from Slurry' tab on mrmalty.com. Anyone know if this is covered in the book? Based on his comments on Brew Strong, it seems like he does a less involved version of this thread's approach (i.e., a single rinse with less water), but I don't know if he considers that a "slurry" or something else.
Do you actually even have to wash it I just pour the top layer off into a mason jar and sealed it in my fridge and it looks like your picture on the left now in my fridge can I repitch this?
Then when it's time to make a starter, you just pull one out, let it warm to room temp, and decant most of the liquid out of the jar, give the rest a good shake, and pitch it into your starter.
You are using 1 of the small mason jars for the starter, correct? Just confused about the give the rest a good shake, and pitch.
Excellent write up and thank you. :rockin:
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