How I Rehydrate Dry Yeast In Ten Easy Steps

[beers]

But why? Where is your data?

For now, I'll keep on doing things my way - I'm happy to have my opinion changed, but "just do it this way" with no explanation or data won't go any way to changing my mind.

So I propose an experiment:

Mobrien,

No need to test your theories as the research has all been done before by a leading yeast authority. See here for a full description of what happens when you re-hydrate dry yeast and why you should not use wort for the best results.

David

Nice article David.
It's a shame that he doesn't elaborate on the "Very dilute wort seems to be OK." comment.

 

[mobrien]

bigfridge - thanks for the data! The nice quote I think is:

"The water should be tap water with the normal amount of hardness present. The hardness is essential for good recovery. 250 -500 ppm hardness is ideal. This means that deionized or distilled water should not be used. Ideally, the warm rehydration water should contain about 0.5 - 1.0% yeast extract.

For the initial few minutes (perhaps seconds) of rehydration, the yeast cell wall cannot differentiate what passes through the wall. Toxic materials like sprays, hops, SO2 and sugars in high levels, that the yeast normally can selectively keep from passing through its cell wall rush right in and seriously damage the cells. The moment that the cell wall is properly reconstituted, the yeast can then regulate what goes in and out of the cell. That is why we hesitate to recommend rehydration in wort or must. Very dilute wort seems to be OK. "

The tests might be worthwhile afterall, if very dilute wort (the question of this thread!) "seems to be ok"!

M

Edit: I can't smell

 

[wessmith]

And as I have posted on several occasions in the past, Lallemand and Fermentis use very different drying techniques in their respective production processes. That is why Lallemand say "only use water" and Fermentis says "water or wort". Why not believe the manufacturer! I can tell you that we ALWAYS use wort when rehydrating Fermentis products. Pitching rates are usually 60-70gms/HL for ale yeasts and 100-120gms/HL for lager yeasts - unless of course you want to develop some distinct ester characteristics when we pitch around 70% of those values to get a longer lag time.

In 800ltr and 1000ltr brew lengths we find terminal gravities for the ale yeast styles achieved in 3 to 4 days at 18C and 6 to 8 days at 10C for the lager styles.

Mobrien, measuring CO2 production may not be all that accurate as the respiration rate of yeast will depend on the pitching rate and the corresponding lag time - ie how long does the yeast take to multiply before getting on with the task of making alcohol.

Of course all of the above assumes that you have the optimal environmant for the yeast to ferment properly. Any shortage of nutrients will skew the results. Interesting that Dr clone stresses the need for a certain calcium level in the rehydrating water for his companies yeasts. You will of course find those same calcium levels in wort.....

Wes

bigfridge - thanks for the data! The nice quote I think is:

"The water should be tap water with the normal amount of hardness present. The hardness is essential for good recovery. 250 -500 ppm hardness is ideal. This means that deionized or distilled water should not be used. Ideally, the warm rehydration water should contain about 0.5 - 1.0% yeast extract.

For the initial few minutes (perhaps seconds) of rehydration, the yeast cell wall cannot differentiate what passes through the wall. Toxic materials like sprays, hops, SO2 and sugars in high levels, that the yeast normally can selectively keep from passing through its cell wall rush right in and seriously damage the cells. The moment that the cell wall is properly reconstituted, the yeast can then regulate what goes in and out of the cell. That is why we hesitate to recommend rehydration in wort or must. Very dilute wort seems to be OK. "

The tests might be worthwhile afterall, if very dilute wort (the question of this thread!) "seems to be ok"!

M

Edit: I can't smell

 

[Ash in Perth]

This probably isnt practical for homebrewing, but dry wine yeasts acheive the greatest viability when re-hydrated for 15min at 40DegC then cooled down to pitching temp. Its odd that those kinds of temperatures can be lethal to yeast.

 

[Adamt]

I currently rehydrate with a procedure that is a mix of the opinions expressed.

I first pitch the yeast into stirring warm water, cover for 20, then add a small amount of wort.

This way I'm rehydrating with water preventing sugar entering the yeast cells, and then preparing the yeast for the wort I'm putting it in.

Awesome post mo!

 

[Kai]

And as I have posted on several occasions in the past, Lallemand and Fermentis use very different drying techniques in their respective production processes. That is why Lallemand say "only use water" and Fermentis says "water or wort". Why not believe the manufacturer! I can tell you that we ALWAYS use wort when rehydrating Fermentis products.

Can you expound a little on this please, wes? I am too lazy so search the respective sites, and it seems so different to the basic knowledge I have at this point regarding any dried yeast.

 

[Screwtop]

If we took a rock with a hole through it and put a log through it, then ran it along the ground until the edges wore off, this round thing could be very usefull, I have a name to call it, how's about "The Wheel"

 

[bigfridge]

And as I have posted on several occasions in the past, Lallemand and Fermentis use very different drying techniques in their respective production processes. That is why Lallemand say "only use water" and Fermentis says "water or wort". Why not believe the manufacturer! I can tell you that we ALWAYS use wort when rehydrating Fermentis products.

Can you expound a little on this please, wes? I am too lazy so search the respective sites, and it seems so different to the basic knowledge I have at this point regarding any dried yeast.

Kai,

The specsheets are available for SafAle US-56 and SafLager 34-70 at the Fermentis website.

David

 

[mika]

I'm with MO...had too many yeasts not take off making me panic and pitch a second yeast.
My 2c anyway.

P.S. Slowly moving towards liquid yeasts so will stay out of these arguments in the future

 

[Slurpdog]

Seems like Adamt has taken the science of both methods and combined both their advantages.
I've never re-hydrated in the past but will rehydrating give a better chance of a lower FG?
All my beers seem to finish quite high (1014-1018) with an average OG of about 1050-1052.
If this re-hydrating caper will acheive a lower FG then I'll definitely give it a go!

 

[mika]

Yeast may not be to blame for your high FG...look closely at the fermenables in your brew

 

[Brewtus]

This may be a little left field but when I bake if I rehydrate the yeast in luke warm, 25deg, water the bread/dough/whatever raises quicker. If I throw in a pinch of sugar, it is even quicker still. Even though it is not some super special beer yeast, ie defiance, it is still saccharomyces cerevisiae, ale yeast, and should react the same.

FTR I do not use wort when baking nor baker yeast when brewing and in all cases prefer to rehydrate when I can..

 

[Darren]

I think the only reason to re-hydrate in a seperate smaller container is to ensure the yeast is still alive. If it don't bubble don't use it.

cheers

Darren

 

[Sammus]

I currently rehydrate with a procedure that is a mix of the opinions expressed.

I first pitch the yeast into stirring warm water, cover for 20, then add a small amount of wort.

This way I'm rehydrating with water preventing sugar entering the yeast cells, and then preparing the yeast for the wort I'm putting it in.

Awesome post mo!

Exactly what Lord Palmer recommends, and I'm guessing for the reasons indicated in this post and thread.

For the record, I do it this way was well (when I use dry).

Edit: and doubley for the record, doing it with water is rehydrating, doing it with sugar/wort is proofing (as I understand anyway)...

 

[Kingy]

Hi i need a little help :unsure:

just tried to rehydrate yeast for the first time.

filled my schooner glass up just over half way with cooled boiled water to 28 degrees added the yeast that comes with a coopers kit stirred every 3 mins and 1 hour later nothing has happened except me drinking more beer and staring at it.

1.what have i done wrong

2.is it still ok to add to fermenter

3.should i put a little dextrose in there

4.should i halve it bcoz i filled the schooner up to much and add a little dextrose to the halved glasses

5.i dunno

6.drink more beer and wait.


p.s i think this thread has confused me

7. ditch the whole lot and throw a spare yeast into the fermenter.

8. maybe through the failed rehydrating exercise yeast in and also throw a differant yeast in all together (blu mountain lager and a coopers lager yeast?)


edit.add 8th step lol

 

[lonte]

2.is it still ok to add to fermenter

yes.

 

[Kingy]

doesnt matter FFS i rehydrated my yeast in an empty schooner glass that i just finished drinking from grrrr.... and the iodopher soaked glass is just sitting there. Looks like this one is gunna taste like crap.

doesnt matter i brought the coles brand for the first time ever just to see if it turns out better than a brew shop brand. looks like its gunna taste like ****. im cursed by coles.

Waiting on my 2 keg setup to arrive,was due to arrive today im not gunna put this in the kegs ill bottle this ruined one and get some proper stuff tomorrow and brew a decent kit for the kegs.

i think i was cursed

im getting sick of k+k its not challenging enough and i fall asleep doin it. Now my kegs are nearly here AG is looking the go.

 

[Keifer]

Some good reading on different approaches to yeast re-hyrdation.

Kingy, if your sick of kk coz it's not challenging, are you doing specialty grains and hops with em ?

 

[PistolPatch]

I wrote this email to someone a few months ago so might as well throw it into the ring. This gives you something to do while brewing in case you arent drinking. Only has 9 steps though

Creating A Mini-Starter including Rehydration of Yeast

You Will Need

1 x Sachets of Yeast
1 x Coffee Mug
1 x 250ml Pyrex Jug
1 x 500ml Pyrex Jug
1 x 750ml Bottle with Lid or larger (e.g. soft drink bottle)

Directions

1. Prior to Mash In: bring a half kettle of water to the boil. Leave to cool.

2. Duriing Mash In: Ensure jugs, mug and bottle are clean and then sprayed with no-rinse sterilizer. Cover them with plastic.

3. At Boil Start: By this stage the boiled water should have cooled 25-30 degrees. Until you can judge this by touch, use a clean thermometer that has been sprayed with no-rinse sanitizer. If the temperature falls within the 22-32 degree range then pour 110ml into the 500ml jug. Sprinkle the 11g sachet of yeast onto the top of the water. Do not stir. Cover with fresh plastic and let it sit.

4. 5 Minutes After Start of Boil: Regardless of whether you have added your boiling hops or not, remove a mugful of wort from the kettle. Pour 250mls into the 250ml jug to half fill it. Cover with plastic and place in a sink of 25 degree tap water.

5. 20 Minutes After Start of Boil: By this stage hopefully your yeast will have formed a milky solution with a creamy head. Often it wont. Dont worry, just continue as follows. Remove the 250ml jug of wort from the sink. As you did in Step 3 above, ensure the wort is in the 22-32 degree temperature range. Add 40mls of wort to the rehydrated yeast in the 500ml jug.

6. 30 Minutes After Start of Boil: Add another 80mls of wort to the 500ml jug.

7. 40 Minutes After Start of Boil: Add remaining wort to 500ml jug.

8. 60 Minutes After Start of Boil: Pour the entire contents of the 500ml jug into your bottle. Screw on lid and shake. Release pressure and repeat occasionally until wort has chilled.

9. Chill End: Pour bottle contents into bottom of fermenter and syphon in wort. Or vice-versa! (Who knows)

P.S. Thanks Screwtop for the bottle shaking idea. The above seems to get things happening very quickly.

 

[Kingy]

Some good reading on different approaches to yeast re-hyrdation.

Kingy, if your sick of kk coz it's not challenging, are you doing specialty grains and hops with em ?

nah still aint worked it out yet :unsure:

therez some good threads on AHB but there are so many differant oppinions on "the next step" so to say threads, that it throws me in a distorted heap. and it just loses me.

ATM All Grain sounds easier to me. and id rather jump straight to doing that.

coz i know in the long run im gunna end up doing that anyway.

im only 24 as well so if start now, by the time im 30 i should be killin it. :super:


edit: spelling