Dry yeast internal nutrient reserves

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big_len

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It is often stated that dry yeast is packaged with optimal nutrients and so forth stored within the cells and I don't think anyone would debate that as a matter of fact.

What confuses me is the different interpretations of that the prupose and utility of these nutrients - and I have not had much joy in researching this, so I am asking here for some genuine input.

Some people seem to think that this is a free nutritional boost for their yeast, that the yeast manufactures went to lengths to give them a 2-for-1 deal on some yeast and nutrients in one packet.

Is it not the case, however, that these nutrients are required because dry yeast must be rehydrated in water, which is devoid of such nutrients for the yeast to feed upon? So it has to bring a reserve to feed on until the process of rehydration is complete and it is subsequently introduced to the nutrient rich wort? It makes sense as, in the absence of such reserves, the yeast would be rehydrated in water and begin to go dormant fairly quickly in the absence of any sustenance.

This also seems to be supported the recommendation that dry yeast should be rehydrated within ~30 minutes of pitching - as these internal reserves can only sustain the yeast in water for that length of time. If that is also the case, then it strikes me that these reserves, in the grand scheme of things with 5 or 10 gals of wort involved, do not contribute much outside of the rehydration phase?

I say again, I only post this hypothesis because I am having a hard time finding information to the topic, and I am perfectly open to any information to the contrary.
 
Never bothered to worry about it.... I just rehydrate, pitch in about 15 minutes, with yeast nutrient previously added to the batch in the fermenter - actually, have never needed/used nutrient for beers, just for meads as honey is lacking in necessary nutrients that wort has.
 
The main component of the "nutrient package" in dry yeast is sterols to provide the needed O2 during the aerobic lag/reproductive phase of fermentation. That's why it's not as critical to oxygenate the wort as when you are using liquid yeast.

The other part kind of functions like the little capsule inside a Wyeast smack pack which gives the yeast just a tiny bit of sustenance to bring them out of dormancy during rehydration and introduction into the wort.
 
BigFloyd --

I'm a big fan of pitching rehydrated Nottingham for most of my beers but I've never added yeast nutrients. I'm making good beer but now I wonder if I should maybe buy some of the Wyeast nutrient and add it to my boil.
I'd be interested in your thoughts on the matter.
 
Wort has all the trace elements and amino acids the yeast need, yeast nutrient really helps in other cases like ciders and meads that are low in those nutrients.


Sent from
 
Wort has all the trace elements and amino acids the yeast need, yeast nutrient really helps in other cases like ciders and meads that are low in those nutrients.


Sent from

Quite true. Depending on your water profile, however, a helpful thing that added yeast nutrient can provide is zinc.

Some German brewers would put a galvanized bolt in the brew pot since the Reinheitsgebot prohibited adding stuff like powdered zinc compounds.
 
The trick is to have a short rehydration phase. The yeast only need seconds to rehydrate enough to avoid osmotic shock. I give it five min to be safe. There are several compounds that make up the 'reserves'. We've explored this recently in the thread "starter with dry yeast". There is a lot of back and forth, but some really great info came out of it! Check out the link provided by Boydster.

Sent from my SCH-R970 using Home Brew mobile app
 
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