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Author Topic: yeast starter from dry yeast  (Read 16622 times)

Offline Steve Ruch

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Re: yeast starter from dry yeast
« Reply #15 on: February 25, 2016, 03:44:21 pm »
The nice thing about dry yeast is that (paraphrasing from S. Cerevisiae and the Lallemand website) it is propagated in a manner that results in high levels of ergosterol and UFA reserves.  As such, you do not really need to aerate/oxygenate your wort on an initial pitch.

Is that also true for big beers: over 1.100?
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Offline narcout

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Re: yeast starter from dry yeast
« Reply #16 on: February 25, 2016, 04:11:04 pm »
Below Dr. Clayton Clone states that Lallemand dry yeast has sufficient lipids for 3 to 4 growth cycles.  In theory, if you require more cells than that, you should either pitch more than one packet or add additional oxygen at some point in the fermentation (that is also touched on in the below).

http://www.lallemandyeast.com/articles/crabtree-effect-and-overflow-metabolism

To paraphrase SC again, the osmotic pressure placed on yeast cells in a high gravity wort is another reason to pitch more cells when brewing high gravity beers.  See reply #46 in this thread:  https://www.homebrewersassociation.org/forum/index.php?topic=24439.msg311523#msg311523

Here's some more info from Dr. Clone in response to a question concerning rehydrating but which also seems applicable to the question of making starters with dry yeast:

https://koehlerbeer.wordpress.com/2008/06/07/rehydrating-dry-yeast-with-dr-clayton-cone/

"We recommend that the rehydrated yeast be added to the wort within 30 minutes. We have built into each cell a large amount of glycogen and trehalose that give the yeast a burst of energy to kick off the growth cycle when it is in the wort. It is quickly used up if the yeast is rehydrated for more than 30 minutes. There is no damage done here if it is not immediatly add to the wort. You just do not get the added benefit of that sudden burst of energy."

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Offline euge

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Re: yeast starter from dry yeast
« Reply #17 on: February 25, 2016, 04:32:33 pm »
I'm a primary user of dry yeast but they have to be handled properly. Or at least the Lallemand does. I expect they all have similar rehydrating and pitching characteristics.

Benefit is an "instant-starter" so making a starter out of dry yeast is redundant. However, mishandling causes problems enough to make you wish you'd made a starter. Reading the product sheet reveals essential tidbits like attemperating the yeast pitch to wort temp in 10* increments or risk yeast mutations in the case of Munich yeast.
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Offline unclebrazzie

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Re: yeast starter from dry yeast
« Reply #18 on: February 26, 2016, 05:14:53 am »
My 2 cents.

As already stated repeatedly above, dry yeast is "prepared" to get cracking the moment it gets rehydrated. It's primed and good to go as it is, ergo it is unnecessary -and in fact downright detrimental to yeast performance to make a starter from a pack of dry yeast. Not sure if this applies to strains like saflager as well though.

As to "one should not"...that sounds a bit silly. I mean, you can easily rack a second beer on top of a yeast cake originating from a previous fermenation started with dry yeast. That's not the same thing as a starter but as close to it as I care to reckon. You could just as successfully make a starter from a single packet to arrive at a cell count which would be more suitable for (say) a big-ass imperial stout, or a 10 gallon batch instead of 5.
From my understanding, it'd still not be as efficient as simply ptiching more packets, but at the end of the day, the packets contain healthy yeast, which you can use either to brew or to propagate.

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Offline kgs

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Re: yeast starter from dry yeast
« Reply #19 on: February 26, 2016, 06:32:43 am »
I'm a primary user of dry yeast but they have to be handled properly. Or at least the Lallemand does. I expect they all have similar rehydrating and pitching characteristics.

Benefit is an "instant-starter" so making a starter out of dry yeast is redundant. However, mishandling causes problems enough to make you wish you'd made a starter. Reading the product sheet reveals essential tidbits like attemperating the yeast pitch to wort temp in 10* increments or risk yeast mutations in the case of Munich yeast.

Euge, thanks to you, I have learned the word "aliquot." In practice, it sounds as if attemperation would only need one interval (if the yeast is ca. 75f after 20 minutes, and your wort is even as low as 50f, and intervals are 50f, then it seems one dollop of wort for 10 minutes would do the trick??).

http://www.murphyandson.co.uk/datasheets/munich%20wheat%20yeast_tech.pdf

https://en.wikipedia.org/wiki/Aliquot
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Offline euge

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Re: yeast starter from dry yeast
« Reply #20 on: February 26, 2016, 07:35:11 am »
I was able to drop the yeast pitch 20* to wort temp (67-68*) in three "aliquots" of 125ml each. Took more than expected (ended up pitching 500ml) but was also being gentle with the process.

Lag time was quite short.
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

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