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Cato

Re-hydrating yeast?

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Hi all, I'm new to brewing and working with a Mr beer kit. 

I have been reading John Palmers, How to Brew book and in reading about yeast he describes how to rehydrate your yeast before pitching.

I have been sprinkling mine on top of the wort in the LBK and then closing it up for 3 weeks.

Do you rehydrate your yeast before pitching?

 

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You can if you want but there's really no need to.  They re-hydrate just fine after being sprinkled on top of the wort.

 

Welcome to the forum!

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1 hour ago, Cato said:

Hi all, I'm new to brewing and working with a Mr beer kit. 

I have been reading John Palmers, How to Brew book and in reading about yeast he describes how to rehydrate your yeast before pitching.

I have been sprinkling mine on top of the wort in the LBK and then closing it up for 3 weeks.

Do you rehydrate your yeast before pitching?

 

I do for danstar yeasts from time to time but not for any fermentis yeasts. I have noticed shorter lag times by rehydrating. Not necessary at all, even the manufacturers specs says you dont have to. Check it out:

220D5BB6-C029-406F-8224-94683412D476.jpeg

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Thanks for the replies on my posting question.

Glad to know that part of my batches creation was okay.

I'm in the baby steps of this and very curious to see how I did on the two batches in the works.

First one is Oktoberfest that came with the kit, and it's in bottle conditioning. Second one is Bewitched Amber

With an LME smooth, and it's fermenting in the LBK.

 

 

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1 hour ago, Creeps McLane said:

I do for danstar yeasts from time to time but not for any fermentis yeasts. I have noticed shorter lag times by rehydrating. Not necessary at all, even the manufacturers specs says you dont have to. Check it out:

220D5BB6-C029-406F-8224-94683412D476.jpeg

 

 

Note that even for lager yeasts they say to pitch above 68 F,  then one expects to reduce the temp to fermentation range. e.g. 12°C – 15°C (53.6-59°F) for W37/40.

 

I often pitch (dry yeast) warm and then as soon as I see some signs of fermentation (a few hours usually) I put the LBK in the cooler.

 

 

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rehydrating modern dry yeast, if you are pitching enough , isnt necessary in most cases.   the reason you rehydrate:  dry yeast is encapsulated with 'food' and put into kind of a state of hibernation.  when they hit water, the cells puke out their stomach contents and begin pumping in whatever liquid they find themselves in.  when first brought back to 'life' the cell walls tend to be fragile.  if they start sucking in high gravity wort the cell walls can rupture (osmotic shock), killing a percentage of your yeast cells... maybe up to 50%.  if you pitch enough yeast for a 5 gallon batch in a 2 gallon wort batch,  even if you have 50% cell die off you still end up with plenty cells to do the job.  the dead cells feed the living and life goes on.

 

when you rehydrate in water at the correct temperature, (the gravity of water is low ie 1.0.)    it is gentle on the cell walls. they suck in the water and then begin the cycle of reproduction / budding if needed... otherwise they immediately start tearing into the available food.  (less lag time).

 

so pitch enough yeast. pitch fresh yeast.  if you do this you really dont need to rehydrate most of yeasts. 

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8 hours ago, zorak1066 said:

rehydrating modern dry yeast, if you are pitching enough , isnt necessary in most cases.   the reason you rehydrate:  dry yeast is encapsulated with 'food' and put into kind of a state of hibernation.  when they hit water, the cells puke out their stomach contents and begin pumping in whatever liquid they find themselves in.  when first brought back to 'life' the cell walls tend to be fragile.  if they start sucking in high gravity wort the cell walls can rupture (osmotic shock), killing a percentage of your yeast cells... maybe up to 50%.  if you pitch enough yeast for a 5 gallon batch in a 2 gallon wort batch,  even if you have 50% cell die off you still end up with plenty cells to do the job.  the dead cells feed the living and life goes on.

 

when you rehydrate in water at the correct temperature, (the gravity of water is low ie 1.0.)    it is gentle on the cell walls. they suck in the water and then begin the cycle of reproduction / budding if needed... otherwise they immediately start tearing into the available food.  (less lag time).

 

so pitch enough yeast. pitch fresh yeast.  if you do this you really dont need to rehydrate most of yeasts. 

 

77B47B4D-C8AE-4315-82B8-BECC68A52FA9.png

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