DurtyChemist
Well-Known Member
Cry Havoc wash I did yesterday. These are 1 quart jars. I will test attenuation on my next batch since there was no OG reading for this brew. Is the brown stuff dead yeast or trub?
Yeast Washing Illustrated
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Cry Havoc wash I did yesterday. These are 1 quart jars. I will test attenuation on my next batch since there was no OG reading for this brew. Is the brown stuff dead yeast or trub?
top layer looks like trub to me. the white pretty stuff on bottom looks like yeast
BGBC
Well-Known Member
The results of my first attempt at washing yeast. Harvested some wyeast 1056 from a batch of honey porter. The illustrated guide was very helpful. Keeping my fingers crossed for no infections and looking forward to using this in future brews!
dang, absolute record. 4 hours after pitching my starter it's bubbling like a maniac
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Can't argue with fresh yeast.
very true, fresh yeast always yields the best result. but what's the percentage difference or perceivable difference between them is the question. I've used washed yeast that's 3+ months old and the difference is so negligible that it's not even funny. just brewed with 6 month old yeast right now and It's taken off like a monster and smells n tastes like a million bucks.
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A lot of it has to do with the type of yeast too. From that Brew Strong episode they mentioned the Hefe yeast will start to give off flavors if it is not used within a couple of weeks. They did say other yeasts can last for several months after being washed/rinsed with no ill affects.
hmmmm, funky, maybe i just can't tell the difference, I can barely tell the difference in hefe's I've made with fresh or months old yeast :shrug:.... interesting to know though.
The part I don't get about this idea is age of the yeast after what? Harvest? So if you make a fresh starter it should reset the clock? White Labs and Wyeast make the yeast basically the same way we do.
DurtyChemist
Well-Known Member
pabloj13 said:
Fresh being new tube/smack pack bought from the store
Month old from first harvest I believe.
Sorry if I missed this as I didn't read the whole thread (but lots of it). I know that most say not to use rinsed yeast after a year or so, but what if I make up another batch and get another generation of yeast and rinse that. Does that reset the clock? So then I have a year more with that yeast?
I'm assuming so, but just want to make sure I'm not missing anything.
I'm assuming so, but just want to make sure I'm not missing anything.
Im kinda stumpped here on trying to harvest yeast from a new vial. I make 2.5 gallon batches. So how big a starter do I need to get like enough for 5 batches? And what do I put it in just preboiled water/jars? Do I need to worry about trub from the dme? Or can I just split the whole starter up into 5 jars or do I need to wash it some? And how many days? Then when I make a batch just make a single starter for a jar? I would like to use it over a period of 6 months-bad idea?
I want to do it this way because it would be cleaner than making a batch then harvesting/washing from a batch or no?
I want to do it this way because it would be cleaner than making a batch then harvesting/washing from a batch or no?
Is all the harvested yeast still viable after a month? 2 months? 6 months? 1 year? In other words, using 1.5 billion yeast cells per mL, as given by Daniels, are all 1.5 billion cells still active and viable?
SMc0724 said:
I'm assuming the 1.5B/ml is in reference to a thick slurry and not yeast in suspension. Yeast loses viability rapidly after about 2 weeks of fridge storage. Either of the calc sites should give you a good estimation of viability based upon age. At more than 9 months I'd expect < 10% viability
So if I use washed yeast to make a starter, then brew a beer and then rinse the resulting yeast cake, does that reset the clock? Or is it from the first time I brewed with it?
zeg
Well-Known Member
If you believe the documentation for the MrMalty yeast calculator, a thin slurry ("yeast just in suspension and will pour smoothly") is about 1 billion cells/mL and near solid-packed yeast is about 4.5 billion/mL. So 1.5 billion/mL is probably a moderately thin slurry.
The MrMalty default is 2.4 billion/mL if that means anything.
mtnagel said:
Brewing a beer an then washing the yeast against "resets" the viability clock. However the yeast your harvesting is also now a generation older.
Yep, got it. Thanks!
BGBC
Well-Known Member
How many generations do people typically reuse their yeast for? I've seen 5 or 6, but has anyone tried more? What impacts could using 'older' yeast (add'l generations) have on your brews?
zeg
Well-Known Member
Results vary depending on many things. Better sanitation and gentler treatment of yeast will allow for more. Some types of yeast hold up better than others. The type of beer you're brewing is also a factor, since some types rely more on the yeast's flavor (etc) properties than others. Finally, how sensitive you are to maintaining the same properties and avoiding off-flavors will affect this.
There are a few things that happen. Assuming you're handling the yeast well enough that they're not being stressed, the yeast themselves will keep being yeast essentially indefinitely. In that case, the main problems are mutation of your selected strain and contamination by bacteria and wild yeasts.
Mutation is encouraged by the selective pressure you apply by your technique. Probably the biggest (or at least easiest to understand) factor here is the flocculation behavior---depending on how and when you rinse the yeast, it's common to collect the most (or occasionally least) flocculant yeast from the batch and then propagate only those. This has more profound effects than just yeast haze, as the flocculation also affects other aspects of fermentation, such as attenuation ability.
Contamination is sort of obvious, I guess. Since you're just harvesting whatever happens to be floating in the beer, over time organisms other than your desired yeast strain will tend to increase in number. Eventually they'll be numerous enough to affect the results, either through an obvious infection or by more subtly changing the flavors you get.
If you're not being very good to your yeast, then you can have other problems as well.
Sorry, which calc sites?
Pickettj
Well-Known Member
So is it not possible to take a wyeast pack or white labs vial and raise your own yeast? Keeping the yeast out of beer until you've cultivated a seperate colony for brewing with? In other words, have a mother colony and only use the sisters(?) for brewing.
Pickettj
Well-Known Member
Pickettj said:
If this isn't possible then how do they fill the smack packs and vials to begin with?
zeg
Well-Known Member
Yes, and this is exactly what the big labs do (at least, in principle). Keeping a strain pure and resisting unwanted mutations for more than a few generations is more complicated than just feeding the yeast, though. At that point you need to be growing pure colonies from single cells and various other microbiological parlor tricks. The yeast really aren't interested in making good beer, they just want to reproduce and evolve, so it takes a lot of effort to keep them in line.
(Even with the mother/daughter colonies, eventually the mother colony will mutate or become contaminated, at which point you've got to very carefully select a few individual cells and then figure out which of them is the one you want to use for your new mother, since the others may be gnarly mutants.)
Pickettj
Well-Known Member
zeg said:
So are we talking microscopes and petry dishes here?
zeg
Well-Known Member
Petri dishes and slants. Microscopes are perhaps helpful, but I don't think required. Also, more critical sanitation requirements---you probably don't want to be doing this in your kitchen or brewing area. (I don't have experience with this, but I happen to have been reading about the techniques lately.)
thanks.
mrmalty site says 10% viable;
yeastcalc says 45% viable.
That is a big difference. Is this just a wild a** guess, or what?
zeg
Well-Known Member
Probably the answer is "sort of." The data may be taken under different conditions, and the results almost surely depend on the strain in question.
My suspicion (which is mostly a WAG as well) is that those calculators are ok for relatively fresh yeast and get worse as it ages. (Partly this is obvious---variations have more time to accumulate as time passes, so it's easy to say that at packaging time, the viability is X. Your prediction gets worse as it degrades.)
I would be rather surprised if the 10% number is correct given the number of people who apparently succeed using old yeast. Even so, if you're near or past the expiration date, it'd be prudent to make a small starter with low-gravity (1.020ish) wort and then pitch that into a real starter.
