Yeast washing vs. yeast harvesting (kraeusen skimming)

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Dogslovebeer

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Which method produces better results?
I would imagine that kraeusen skimming is more prone to infecting the beer, but would would gather a stronger sample. Where yeast washing would safer but less effective. or maybe it doesn't matter, just build up a nice starter.

Thank you
 
The only homebrewer I know of who top-crops is Mike McDole. I think he refers to it as "super yeast." He gets his blowoff tube down almost to the beer's surface and the positive pressure of fermentation pushes the kraeusen through.

Washed yeast should be plenty potent if you harvest enough and use it soon.
 
For a single yeast strain, top cropping is probably better only if you can reuse the yeast nearly immediately.

For mixed strains, top cropping is the only way to harvest yeast without getting substantially more of whichever strain is more flocculent each generation.
 
This is good stuff guys, I like the super yeast technique and I'll have to try it. Now I brew almost exclusively Hefe Weizen, I heard that the Hefe yeast will only last a couple of generations. is this true, if so about how many generation's?

Thanks
 
I like the 'starter splitting' method, its one of the easiest and best methods I have seen!
When you are making some starter wort with DME or whatever, make it 1.080 instead of 1.040.
Get a bunch of sterilized (boiled) mason jars and leave about a third of your water in.
Add your yeast to your strengthened starter wort, mix it really well, then top off your mason jars until you have enough. Wait a few days and voila, more starters!
Pitch one of your jars of starter into enough wort to get your cell count for your beer ready to go and you are set.
 
How many generations of yeast would one get before reaching the EOL of the yeast? Or does that happen. All my genetic classes say there would be a EOL or defective yeast if propagated from the very same strain.
 
How many generations of yeast would one get before reaching the EOL of the yeast? Or does that happen. All my genetic classes say there would be a EOL or defective yeast if propagated from the very same strain.

I realize this is an old thread, but I wanted to mention something. Elsewhere on these forums, I've read that hefe yeasts noticably lose their aroma producing properties after the 4th generation. I'm not sure what EOL means, but I'm guessing it's related to "how many batches can I put a hefe yeast through before it's not really hefe yeast anymore".
 
I realize this is an old thread, but I wanted to mention something. Elsewhere on these forums, I've read that hefe yeasts noticably lose their aroma producing properties after the 4th generation. I'm not sure what EOL means, but I'm guessing it's related to "how many batches can I put a hefe yeast through before it's not really hefe yeast anymore".

If that is the case, how would the yeast "manufacturers" breed them? Not to sound like a smarta$$, as I will be the first to admit I am completely ignorant in the ways of the yeasts. (I take the 15th century trappist monk approach short of calling it simply "god is good") It does, however, occur to me that in order to keep a yeast strain pure one must cultivate it from something of an original, shall i say, "blood line". So it makes sense to me that a hefe, belgian, english, american lager, etc. has been duped over and over from much older cells to obtain the same yeast essentially, over many batches. It is hard for me to believe that the "manufacturers" just will a particular yeast strain to grow and put it in a pouch or foil packet. Am I completely off base here?:confused:
 
If that is the case, how would the yeast "manufacturers" breed them? Not to sound like a smarta$$, as I will be the first to admit I am completely ignorant in the ways of the yeasts. (I take the 15th century trappist monk approach short of calling it simply "god is good") It does, however, occur to me that in order to keep a yeast strain pure one must cultivate it from something of an original, shall i say, "blood line". So it makes sense to me that a hefe, belgian, english, american lager, etc. has been duped over and over from much older cells to obtain the same yeast essentially, over many batches. It is hard for me to believe that the "manufacturers" just will a particular yeast strain to grow and put it in a pouch or foil packet. Am I completely off base here?:confused:

This is a good question and something I have wondered, too. I know that yeast can occur naturally and could be found in the air and on plants/fruits... But where would the original source of a particular yeast strain (like the american hefe) be?
 
I use washed yeast all the time, with good results (and a starter).good way to save money, if you ask me.

While at a brewery in alaska this summer, I was told by one of their brew masters they use "recycled" yeast six times without a noticeable difference in aroma or flavor. Their house yeast wasn't a hefe yeast though
 
If that is the case, how would the yeast "manufacturers" breed them? Not to sound like a smarta$$, as I will be the first to admit I am completely ignorant in the ways of the yeasts. (I take the 15th century trappist monk approach short of calling it simply "god is good") It does, however, occur to me that in order to keep a yeast strain pure one must cultivate it from something of an original, shall i say, "blood line". So it makes sense to me that a hefe, belgian, english, american lager, etc. has been duped over and over from much older cells to obtain the same yeast essentially, over many batches. It is hard for me to believe that the "manufacturers" just will a particular yeast strain to grow and put it in a pouch or foil packet. Am I completely off base here?:confused:

I am not a yeast manufacturer but I can tell you that in science class we would have different strains or cultures that were the same batch. We wouldn't take daughter cells to create the new yeast. We would use original cells. In other words, we collect new cells from the same batch and not recycle them. This takes a considerable amount of energy since it is much easier just to take a daughter cell and revive it. But you then pass on weaker DNA strands that begin to fail in subsequent generations.

So, maybe this is how yeast is grown in the lab? Just keeping the main mother cells alive and reproducing. Now, if I do use a daughter cell batch, then I would not try to recover sleepy yeast cells. I would just collect fresh ones and the ones that die, die off naturally.

Also remember that if yeast cells are dormant, they are not expending energy and can actually survive an astounding number of years. I even read that some Egyptian yeast over 5000 years old was recovered. Fungi (yeast) are notoriously hard to kill. There is a really good reason they have thrived over millennia. Also they are very simple creatures being one-cell and using asexual reproduction and all.

Of course, I am not an expert on this. Hopefully someone can explain how Wyeast and White Labs seem to have an never-ending supply of not just ONE yeast... but over 30 different subspecies. Selective breeding gives us the 30 types of yeasts... but they are all from the same species.

If I were to make yeasts to sell, I would separate the mother cells off before exhaustion by placing them in a sterile, cold environment. When not active, yeast can survive a very long time.
 
Like above I don't claim to know this but I would think the yeast labs are not brewing batches of beer in order to propagate their yeast populations. The yeast are probably grown on agar in incubators in the most favorable conditions to promote yeast health.

How awesome would it be though if white labs was really brewing up big old batches of beer all the time to propagate their yeast populations? buy some yeast and get a free six pack.
 
It does not matter really how the commercial yeast manufacturers do it.
Home brewers have different needs.
We want quick starting temperature tolerant yeasts at affordable prices.
The cost of reputed high quality yeast sample is not low.
Most kit brews have yeast which meets our needs very well & are hard to beat & they are included so quite low cost.
When home brewers begin to think about yeast harvesting it is generally to obtain a fast start, reduce cost & sometimes because they are enarmoured with a particular yeast. Once you start to harvest yeast you soon have more than enough & the number of mutation free generations is hardly an issue. Remember also that practicing some of the recommended detailed harvesting, washing, & storing routines is quite time consuming & you soon have a fridge part full of yeast sample bottles.
 

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