Re-hydrating yeast kills?

[Bobby_M]

Man this thread had slow start but eventually got to good info. Just to reiterate, yeast rehydrate at nearly 100% viability in warm water while rehydration in a sugar dense liquid may yield 60% (IOW, 40% of the cells die).

From the Danstar FAQ:

Why is rehydrating the dry yeast before pitching important?

Dry beer yeast needs to be reconstituted in a gentle way. During rehydration the cell membrane undergoes changes which can be lethal to yeast. In order to reconstitute the yeast as gently as possible (and minimize/avoid any damage) yeast producers developed specific rehydration procedures. Although most dry beer yeast will work if pitched directly into wort, it is recommended to follow the rehydration instructions to insure the optimum performance of the yeast.

rehydration instructions for Safalel US05

Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 27°C ± 3°C (80°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle
the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the
wort using aeration or by wort addition.

 

[BansheeRider]

Man this thread had slow start but eventually got to good info. Just to reiterate, yeast rehydrate at nearly 100% viability in warm water while rehydration in a sugar dense liquid may yield 60% (IOW, 40% of the cells die).

From the Danstar FAQ:


rehydration instructions for Safalel US05

Good info! So as long as the wort is above 68 degrees then the yeast won't go into shock? I can see how pitching yeast from 80 degree water to below 68 degree wort can possibly shock the yeast.

 

[zeg]

The rule I've seen is that you don't want more than a 10°F (5°C) jump in temperature between the yeast being pitched and the wort it's being added to. From other threads and the 71b-1122 data sheet, rehydrated yeast lose viability about 45 minutes after rehydration because they deplete the reserves that were stored with them.

Because of this, waiting for the rehydrated slurry to drop to the pitching temperature can be too slow. For some yeasts, the advice is to add small quantities of wort and mix them, wait a couple minutes, and repeat. This can bring the slurry to pitching temperature faster than waiting, but slow enough to avoid a thermal shock.

In most cases, the pitch rates are high enough with dry yeast that we're picking at details with a lot of these concerns, though. Other than major errors (like cooking the yeast), more than likely enough yeast will survive that you'll be within a factor of a few of the pitch rate you're after. I think for most of us, that's close enough that it's unlikely to be the difference between a good and a bad beer.

 

[BansheeRider]

The rule I've seen is that you don't want more than a 10°F (5°C) jump in temperature between the yeast being pitched and the wort it's being added to. From other threads and the 71b-1122 data sheet, rehydrated yeast lose viability about 45 minutes after rehydration because they deplete the reserves that were stored with them.

Because of this, waiting for the rehydrated slurry to drop to the pitching temperature can be too slow. For some yeasts, the advice is to add small quantities of wort and mix them, wait a couple minutes, and repeat. This can bring the slurry to pitching temperature faster than waiting, but slow enough to avoid a thermal shock.

In most cases, the pitch rates are high enough with dry yeast that we're picking at details with a lot of these concerns, though. Other than major errors (like cooking the yeast), more than likely enough yeast will survive that you'll be within a factor of a few of the pitch rate you're after. I think for most of us, that's close enough that it's unlikely to be the difference between a good and a bad beer.

Ok sounds good. I normally cool my wort to just below 80 degrees before pitching the yeast. If I hydrate the yeast in 90 degree water then it shouldn't be an issue regarding pitching temperature.

 

[jonmohno]

Ok sounds good. I normally cool my wort to just below 80 degrees before pitching the yeast. If I hydrate the yeast in 90 degree water then it shouldn't be an issue regarding pitching temperature.

Ive had pretty fruity beers pitching at that temp,if you like it then have at. I havent done that since my first few beers,which I think is way to high. You could get too fast a ferment as well as alot of esters. Ive always had good beers with nothing off hydrating at recommended temps then pitching at ferm temps. It does seem that you should add some wort after 15 min to ease it into your main pitch wort temp. Its really only about viability loss. So if you pitch more than enough dry yeast then you can pitch dry or hydrate and pitch the 20 degree difference and still afford some of the viability loss. Although it does stress and add loss of viability but again, if you overpitch you shouldnt have to worry too much about the temp difference. Although its better to strive for optimum yeast viability.
Also if your pitching just below 80 what temps does that mean your fermenting at? More than 10 deg drops can stress yeast(maybe more?) that way if you ferment in the mid low 60's that way. And its generally more estery fermenting above 70 to ferment in most yeast it seems anyway if your primarily fermenting that high.
So long story short: you may be getting more stressed yeast pitching @ 80 and fermenting above 70.

I dont generally hydrate- then add cooled(primary temp) wort- then pitch to main wort. I generally overpitch-hydrate, then just throw the hydrated yeast in to wort below or close to 70. If I knew I wasnt overpitching then I would add wort after hydration to get it closer to primary pitch temps.

 

[Dynachrome]

I use tepid tap water with a little table sugar mixed in.

I pour the dry yeast on top and let it sit there. I do not stir it in. I let it do its thing for a few hours.

I swirl it around and dump it into my wort when it is ready.

https://www.homebrewtalk.com/f39/fermentor-experiment-one-yeast-substitution-365182/

I don't stir it once it is in the wort.

 

[jonmohno]

I use tepid tap water with a little table sugar mixed in.

I pour the dry yeast on top and let it sit there. I do not stir it in. I let it do its thing for a few hours.

I swirl it around and dump it into my wort when it is ready.

https://www.homebrewtalk.com/f39/fermentor-experiment-one-yeast-substitution-365182/

I don't stir it once it is in the wort.

You dont really want to "proof" it like bread yeast. Just hydrate it first. Shure that will work but you will get loss from that as discussed previously.

 

[BansheeRider]

Ive had pretty fruity beers pitching at that temp,if you like it then have at. I havent done that since my first few beers,which I think is way to high. You could get too fast a ferment as well as alot of esters. Ive always had good beers with nothing off hydrating at recommended temps then pitching at ferm temps. It does seem that you should add some wort after 15 min to ease it into your main pitch wort temp. Its really only about viability loss. So if you pitch more than enough dry yeast then you can pitch dry or hydrate and pitch the 20 degree difference and still afford some of the viability loss. Although it does stress and add loss of viability but again, if you overpitch you shouldnt have to worry too much about the temp difference. Although its better to strive for optimum yeast viability.
Also if your pitching just below 80 what temps does that mean your fermenting at? More than 10 deg drops can stress yeast(maybe more?) that way if you ferment in the mid low 60's that way. And its generally more estery fermenting above 70 to ferment in most yeast it seems anyway if your primarily fermenting that high.
So long story short: you may be getting more stressed yeast pitching @ 80 and fermenting above 70.

I dont generally hydrate- then add cooled(primary temp) wort- then pitch to main wort. I generally overpitch-hydrate, then just throw the hydrated yeast in to wort below or close to 70. If I knew I wasnt overpitching then I would add wort after hydration to get it closer to primary pitch temps.

My fermenting temps fluctuate between 68-72 degrees. I have only done one batch of beer (currently in secondary carboy). I pitched the dry yeast at 80 degrees. The next morning the beer was fermenting like crazy at about 70 degrees. Are you saying this will create off flavors? I just ordered a recipe kit, I will try to get my wort to about 70 degrees this time before pitching the yeast.

 

[jonmohno]

My fermenting temps fluctuate between 68-72 degrees. I have only done one batch of beer (currently in secondary carboy). I pitched the dry yeast at 80 degrees. The next morning the beer was fermenting like crazy at about 70 degrees. Are you saying this will create off flavors? I just ordered a recipe kit, I will try to get my wort to about 70 degrees this time before pitching the yeast.

It can. And depends what yeast if you want that or not. Its just something I learned and didnt know even with months of research before brewing,its just something that I didnt come across. Especially when directions say pitch below 80 deg. Yes,but generally that is still to high. JUst give your beer longer and it could still and may turn out very good right away, if its not give it more time and it may get better. There are alot of other things that can account for many different characters that may even be misleading at first when starting out. I was a little frustrated at first and just thought that homebrew may not be good or something.It was only a few things I happed to overlook which took experience and time to figure out.
Is your actuall beer 70 deg or your ambient temps 70? If you feel your fermenter and its pretty warm then you may have somewhat an estery beer.

 

[zeg]

For my first few batches, I pitched in the low 80s or high 70s simply because I didn't yet have a good way to cool the wort and I got tired of waiting. I've not had what I'd call any fruity off flavors. In my case, I used Nottingham dry yeast, pitching two 11g packets. That should be a pretty generous pitch, although it's in line with the recommended numbers that were either on the packet or on the datasheet. That's a yeast that, especially at fermentation temps in the low 60s, tends to be pretty clean. So it's possible I did get some esters but the rest of the fermentation was so clean that they weren't enough to be prominent.

Now that I've got an immersion chiller, I can get down to proper ale temperatures very quickly. For lagers, I just chill it to room temperature, then stick it in the fridge overnight and pitch the next evening in the upper 40s.

 

[BansheeRider]

It can. And depends what yeast if you want that or not. Its just something I learned and didnt know even with months of research before brewing,its just something that I didnt come across. Especially when directions say pitch below 80 deg. Yes,but generally that is still to high. JUst give your beer longer and it could still and may turn out very good right away, if its not give it more time and it may get better. There are alot of other things that can account for many different characters that may even be misleading at first when starting out. I was a little frustrated at first and just thought that homebrew may not be good or something.It was only a few things I happed to overlook which took experience and time to figure out.
Is your actuall beer 70 deg or your ambient temps 70? If you feel your fermenter and its pretty warm then you may have somewhat an estery beer.

The thermometer on my fermenting bucket normally stays between 68-71 degrees, so that would be the beer temp correct?

 

[Stix]

You can kill cells by rehydrating wrong. It is to easy to forget how long or have a bad therometer. Water bad or contaminated. Alot to go wrong. Just as easy to sprinkle it in. A cell in rich wort even though damaged can quickly recover. A dead cell in rehydration does nothing. We can argue all day. In the end its personal choice. Dry yeast is cheap toss 2 packs in if worried.

 

[mammothkraken]

I've been using fermentis dry yeast for a while. Recently I noticed that they have the rehydration instructions on their new pdf and gave it a shot. I have to say it's given me good results.

My method is to reserve 1 liter of wort from my mash. While my boil is going on I sterilize the reserved liter of wort by boiling for 5 minutes in a small sauce pan. I then place the small sauce pan in a larger pot full of water and ice to chill to correct temp (80F for ale yeast, 73F for lager). I sprinkle the dry yeast on top of the chilled wort and let it rest like the instructions advise for 15-30 minutes.

The yeast will go through a series of steps right now. First it will just sit there dry for a few minutes and slowly rehydrate and drop into the wort. Then it will begin to 'proof' similar to the process of proofing if you've ever made bread at home, it will start to have little bubbles/foam rising up to the top across the surface. After 15-30 minutes I will give it a gentle stir and can feel that the yeast is thickening under the wort. Fermentis suggests stirring it gently for 30 minutes...I don't have a stir plate and am far too busy (lazy) during a brew day to do that. I stir it every 10-15 minutes until I'm ready to use it, in between stirs I put the lid for the small sauce pan (sanitized with starsan) over it to keep nasties from joining the party.

I have let it sit in the wort rehydrating for upwards of 2 hours. The other day I was making an IPA and it rehydrated during my 90 minute boil and my 30 minutes of cooling afterwards. By the time I was ready to pitch it was very thick and foamy and took off like a rocket.

The major benefit I've noticed to rehydration in wort is obvious...more yeast cells. I previously would typically use 2 packets of dry yeast for a lager, per the package directions. With rehydration taking place in wort you are basically kickstarting fermentation and therefore I've been able to only use 1 packet and have better results then I was having using 2. With the lager I brewed yesterday I rehydrated 1 packet of lager yeast over the course of 60-75 minutes and pitched at 55F. I saw signs of fermentation within 12 hours. The other benefit I've noticed is that fermentation starts sooner which has always been a downside of dry yeast vs. the ready to pitch liquid. And to top it off I've seen better attenuation on some of my regular brews that were done with dry yeast last time and rehydrated on the more recent batches.

All that said I'm a fan of the rehydration, it costs me little to no extra time and the payoff is totally worth it. Just make sure if you do it that you starsan anything that comes in contact with the wort/yeast/everything...like sanitize the spoon in between every 10 minute stir, if you set the lid for the pan on the counter sanitize it before it goes back on the pan, etc. I know it's beating a dead horse but I think the main reason that they previously recommended against rehydration is the risk for contamination can increase if you're not careful and of course novice brewers would assume it is the fault of Fermentis' product and not their own lax sanitization procedures.

 

[Demus]

You can kill cells by rehydrating wrong. It is to easy to forget how long or have a bad therometer. Water bad or contaminated. Alot to go wrong. Just as easy to sprinkle it in. A cell in rich wort even though damaged can quickly recover. A dead cell in rehydration does nothing. We can argue all day. In the end its personal choice. Dry yeast is cheap toss 2 packs in if worried.

Personal choice is which strain to use, which beer to brew, buckets vs. carboys etc. It's a fact that rehydrating properly results in higher percentage of living yeast cells. It's also a fact that pitching it dry into wort results in about 50% death rate. A dehydrated cell that burst can not recover; it is dead. You can choose to kill 50% of your yeast, but you can't choose for that not to happen unless you rehydrate. It's about the easiest step of a brew day.
-Boil water
-let it cool to about 100 degrees
-sprinkle yeast on about a half cup of warm water
-wait 15 minutes
-stir and pitch
I'm really not sure why you wouldn't want to do this, but as you point out, it's your choice...

 

[Demus]

Why does the temperature have to be so high to hydrate the yeast? And what is the difference between rehydrating and making a starter with DME?

Rehydrating is warm water because the dried yeast will absorb it faster warm. I'm sure cool water would work but would simply take longer.

A starter is completely different though some posters on here are really confusing the two. With a starter you are culturing liquid yeast which needs no rehydration but is generally too few cells depending on gravity and volume of wort. For a starter you use a certain quantity of simple wort (not your beer recipe) to reach a certain cell count over a few days. You then pitch this increased amount of yeast on brew day.

Again:

Rehydrate = a 15 minute process to ensure you don't kill half your dry yeast packet by sprinkling directly to wort.

Starter = a process taking 1 or more days that increases the cell count of a liquid yeast culture to the optimum pitching rate.

Hope this helps...

 

[zeg]

My method is to reserve 1 liter of wort from my mash. [...] I sprinkle the dry yeast on top of the chilled wort and let it rest like the instructions advise for 15-30 minutes.

The yeast will go through a series of steps right now. First it will just sit there dry for a few minutes and slowly rehydrate and drop into the wort. Then it will begin to 'proof' similar to the process of proofing if you've ever made bread at home, it will start to have little bubbles/foam rising up to the top across the surface. [...]

I have let it sit in the wort rehydrating for upwards of 2 hours. The other day I was making an IPA and it rehydrated during my 90 minute boil and my 30 minutes of cooling afterwards. By the time I was ready to pitch it was very thick and foamy and took off like a rocket.

While I don't doubt that your method works, rehydration of modern dry yeasts is most effective in water, not wort. The reason I've seen cited, including earlier in this thread, is that during rehydration, the yeast cell membranes lack the selective permeability to keep toxic components of the wort out of the cell. These chemicals are not found in water, so it's not an issue. Furthermore, the packaged yeast powder contains enough nutrients that the yeast are happy for up to about 45 minutes without any additional nutrition.

The data sheets vary, and Fermentis says wort is ok, but the Danstar Nottingham ale yeast and Lalvin 71b-1122 wine yeast data sheets both specifically instruct not to use wort/must for rehydration.

Based on this, I think you'd have better results (in terms of yeast viability; it may or may not have any impact at all on your final product) if you rehydrated in sterile water instead of wort. Now, if you're going to be waiting a couple hours before pitching, transfering your slurry into a small quantity of wort is a good idea simply because the yeast will use up their initial carbohydrate/fatty acid reserves and start dying if you don't feed them something.

You also mentioned the various phases that your rehydrating yeast go through. I just want to point out that I see essentially all that activity in most of my rehydrations, using nothing but water. I sprinkle the yeast on top and after a short time, the yeast clumps and sinks, and ends up with a thick creamy foam. Unless you need to sustain the yeast for an extended period before pitching, wort isn't necessary to get yeast to "proof" with modern dried brewer's yeasts.

 

[BansheeRider]

I've been using fermentis dry yeast for a while. Recently I noticed that they have the rehydration instructions on their new pdf and gave it a shot. I have to say it's given me good results.

My method is to reserve 1 liter of wort from my mash. While my boil is going on I sterilize the reserved liter of wort by boiling for 5 minutes in a small sauce pan. I then place the small sauce pan in a larger pot full of water and ice to chill to correct temp (80F for ale yeast, 73F for lager). I sprinkle the dry yeast on top of the chilled wort and let it rest like the instructions advise for 15-30 minutes.

The yeast will go through a series of steps right now. First it will just sit there dry for a few minutes and slowly rehydrate and drop into the wort. Then it will begin to 'proof' similar to the process of proofing if you've ever made bread at home, it will start to have little bubbles/foam rising up to the top across the surface. After 15-30 minutes I will give it a gentle stir and can feel that the yeast is thickening under the wort. Fermentis suggests stirring it gently for 30 minutes...I don't have a stir plate and am far too busy (lazy) during a brew day to do that. I stir it every 10-15 minutes until I'm ready to use it, in between stirs I put the lid for the small sauce pan (sanitized with starsan) over it to keep nasties from joining the party.

I have let it sit in the wort rehydrating for upwards of 2 hours. The other day I was making an IPA and it rehydrated during my 90 minute boil and my 30 minutes of cooling afterwards. By the time I was ready to pitch it was very thick and foamy and took off like a rocket.

The major benefit I've noticed to rehydration in wort is obvious...more yeast cells. I previously would typically use 2 packets of dry yeast for a lager, per the package directions. With rehydration taking place in wort you are basically kickstarting fermentation and therefore I've been able to only use 1 packet and have better results then I was having using 2. With the lager I brewed yesterday I rehydrated 1 packet of lager yeast over the course of 60-75 minutes and pitched at 55F. I saw signs of fermentation within 12 hours. The other benefit I've noticed is that fermentation starts sooner which has always been a downside of dry yeast vs. the ready to pitch liquid. And to top it off I've seen better attenuation on some of my regular brews that were done with dry yeast last time and rehydrated on the more recent batches.

All that said I'm a fan of the rehydration, it costs me little to no extra time and the payoff is totally worth it. Just make sure if you do it that you starsan anything that comes in contact with the wort/yeast/everything...like sanitize the spoon in between every 10 minute stir, if you set the lid for the pan on the counter sanitize it before it goes back on the pan, etc. I know it's beating a dead horse but I think the main reason that they previously recommended against rehydration is the risk for contamination can increase if you're not careful and of course novice brewers would assume it is the fault of Fermentis' product and not their own lax sanitization procedures.

Personal choice is which strain to use, which beer to brew, buckets vs. carboys etc. It's a fact that rehydrating properly results in higher percentage of living yeast cells. It's also a fact that pitching it dry into wort results in about 50% death rate. A dehydrated cell that burst can not recover; it is dead. You can choose to kill 50% of your yeast, but you can't choose for that not to happen unless you rehydrate. It's about the easiest step of a brew day.
-Boil water
-let it cool to about 100 degrees
-sprinkle yeast on about a half cup of warm water
-wait 15 minutes
-stir and pitch
I'm really not sure why you wouldn't want to do this, but as you point out, it's your choice...

Your method sounds so easy and I too don't know why one wouldn't want to do this. The poster above you has a good method as well. Hmmm decisions decisions.

 

[Demus]

Your method sounds so easy and I too don't know why one wouldn't want to do this. The poster above you has a good method as well. Hmmm decisions decisions.

He's still rehydrating with wort though. This makes no sense because it's really the same as just sprinkling it into your main wort when you think about it....

 

[BansheeRider]

He's still rehydrating with wort though. This makes no sense because it's really the same as just sprinkling it into your main wort when you think about it....

I think he's trying to avoid shocking the yeast, as discussed earlier in this thread. Hydrating the yeast in 90 degree water and then pitching in 70 degree wort may not work as well.

 

[mammothkraken]

My method has produced better results for me than just sprinkling into the wort. Also I've tried the water rehydration and based on a few trials of each method the wort rehydration takes off faster and has better attenuation but I'm not testing this in a lab...and the end result is the same...beer.
This works good for me but like many things in brewing to each their own.

 

[Demus]

The trouble with such debates is there's always several ways that "work". BansheeRider's post asked a question about rehydration and he indicated being a new brewer. You have to realize, you will often get as many answers as there are members on this forum! The info I have stated on here comes from the book "Yeast", written by Chris White of White Labs and Jamil Zainisheff, homebrewer turned commercial brewer. You can certainly try every method folks swear by, but it's going to take you a long time. There are so many variables involved with yeast, and every one of them effects the final results. My guess is mammokraken has either low enough gravity beer that killing half of the cells in a dry yeast pack didn't have a negative effect. Short lag time isn't the only indicator of a healthy ferment. In fact, it probably means under aeration because yeast absorb oxygen in the lag phase, and short one could indicate a low oxygen wort.
As far as your concerns over temperature "shocking" the yeast, there really is none. By the time 15 minutes has past the half cup of water (now creamy yeast) has cooled to room temperature. It's now the temperature of the wort you and your yeast are concerned with. It should be in the 60's for most ale yeast strains. It's not that warmer temperatures harm the yeast; this is another misconception. It's that yeast produce more off flavor compounds at higher fermentation temperatures. Yeast actually "like" warmer temperatures as indicated by faster fermentation, but you won't like the beer they produce! Enjoy your brewing, and the debates!!! Welcome to brewing!!!

 

[mammothkraken]

My guess is mammokraken has either low enough gravity beer that killing half of the cells in a dry yeast pack didn't have a negative effect. Short lag time isn't the only indicator of a healthy ferment. In fact, it probably means under aeration because yeast absorb oxygen in the lag phase, and short one could indicate a low oxygen wort.

I wouldn't consider these brews from last weekend low gravity:

Double Porter OG 1.086
IPA OG 1.072
NW Lager 1.068

I brew AG and always aerate my wort in the fermentor, using the classic shake it up method for 30 seconds...never had a problem before.

There's more than one way to skin a cat and there's more than one right way to skin a cat. I say experiment with the methods listed here, if one works for you use it!

 

[Stix]

Personal choice is which strain to use, which beer to brew, buckets vs. carboys etc. It's a fact that rehydrating properly results in higher percentage of living yeast cells. It's also a fact that pitching it dry into wort results in about 50% death rate. A dehydrated cell that burst can not recover; it is dead. You can choose to kill 50% of your yeast, but you can't choose for that not to happen unless you rehydrate. It's about the easiest step of a brew day.
-Boil water
-let it cool to about 100 degrees
-sprinkle yeast on about a half cup of warm water
-wait 15 minutes
-stir and pitch
I'm really not sure why you wouldn't want to do this, but as you point out, it's your choice...

You have not read enough about it then. It is a personal choice. Grow up. Its a game of chance both ways... Except damaged cells in wort can recover. They can't in water at the wrong temp or if the water has toxins that can't be boiled out. How do you know what one worked better if they both fermented out just fine? You say 50% die in wort. Well toss in 2 if ya worried. How many die from improper re hydration? Bad water as yeast when first re hydrated cannot determine what is going through the cell walls and can become severly damaged and useless.

 

[Demus]

You have not read enough about it then. It is a personal choice. Grow up.

It certainly is a personal choice, I agree. But the science says sprinkling on wort kills more cells than rehydration in water. What does growing up have to do with it? I wasn't being argumentative, just trying to steer a new brewer in the right direction. Apparently you are trying to do the opposite...

 

[Stix]

Apparently not. Prove what I said was wrong about improper re hydration or bad water? Sprinkling in can kill more cells......But that is only if you re hydrated perfectly and nothing went wrong.... How do you know? You are the one stating its not a personal choice. You are the one that said it is a must do. That is where you are wrong. You cannot tell if there was toxins in the water or the temperature was off. You cannot guarantee all went perfect. Your logic is flawed. I never said sprinkling is perfect, but it is perfectly safe and reliable.

 

[Demus]

Apparently not. Prove what I said was wrong about improper re hydration or bad water? Sprinkling in can kill more cells......But that is only if you re hydrated perfectly and nothing went wrong.... How do you know? You are the one stating its not a personal choice. You are the one that said it is a must do. That is where you are wrong. You cannot tell if there was toxins in the water or the temperature was off. You cannot guarantee all went perfect. Your logic is flawed. I never said sprinkling is perfect, but it is perfectly safe and reliable.

And I didn't say sprinkling dry yeast was wrong, just that it kills 50% of the yeast. If you figure that fact in to your pitch rate calculations and it works, there's certainly nothing wrong with it. If you are so concerned with toxins in your water, why are you brewing with it?

 

[Stix]

And I didn't say sprinkling dry yeast was wrong, just that it kills 50% of the yeast. If you figure that fact in to your pitch rate calculations and it works, there's certainly nothing wrong with it. If you are so concerned with toxins in your water, why are you brewing with it?

Ok you did say that and you did say it was not a personal choice. Do I need to quote you? Your just be ridiculous now. Have a good night. I need not quote ya others can read.

 

[passedpawn]

Apparently not. Prove what I said was wrong about improper re hydration or bad water? Sprinkling in can kill more cells......But that is only if you re hydrated perfectly and nothing went wrong.... How do you know? You are the one stating its not a personal choice. You are the one that said it is a must do. That is where you are wrong. You cannot tell if there was toxins in the water or the temperature was off. You cannot guarantee all went perfect. Your logic is flawed. I never said sprinkling is perfect, but it is perfectly safe and reliable.

If you rehydrate properly, you will have many more living, healthy yeast cells than if you sprinkle directly into wort.

Sure, if you rehydrate improperly, you can have problems. But rehydrating properly is not difficult.

There is zero advantage in reydrating in wort. This only makes the job harder. And, it probably damages the yeast, but I don't have hard evidence of that. Dr. Cone, below, recommends against it.

Don't bother oxygenating wort in which you've pitched dry (or rehydrated) yeast.

Dr. Clayton Cone is a renowned scientist at Lallemand. His word should be considered state of the art:

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

 

[Stix]

If you rehydrate properly, you will have many more living, healthy yeast cells than if you sprinkle directly into wort.

Sure, if you rehydrate improperly, you can have problems. But rehydrating properly is not difficult.

There is zero advantage in reydrating in wort. This only makes the job harder. And, it probably damages the yeast, but I don't have hard evidence of that. Dr. Cone, below, recommends against it.

Don't bother oxygenating wort in which you've pitched dry (or rehydrated) yeast.

Dr. Clayton Cone is a renowned scientist at Lallemand. His word should considered state of the art:

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

http://onlinelibrary.wiley.com/stor...1999.00638.x.pdf;jsessionid=BFE7F71617217A7FE 43ED01667E0BD99.d04t03?v=1&t=ha2ode6g&f90ad15f



I agree with you. It is easy but not fool proof. Any toxins in the water or container can and will kill yeast. To what extent you will never know could be 20% or 50% or more. You never know whats in any water.

You have to remember this article which explains why re hydrating can be detrimental. Also it explains how even damaged cells can recover in rich wort. Also they talk of this 50% number always tossed around.

www.fermentis.com/shared/Doc_60698.pdf

May aswell toss this in there. To each there own. Brew and be happy. Also be informed of all the drawbacks of each and make your personal choice. Your the brewer not the people on the forums.

 

[helibrewer]

There really is no reason to not rehydrate. I also use a little nutrient, like GoFerm when doing it. I have always rehydrated my wine yeast and although I primarily use liquid yeast, I have used dry on occasion and always rehydrate it. But then again, I would never use liquid without a starter either. Yeast is by far the most important ingredient in the beer, you might as well give it every advantage.